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MINI VGA2HDMI Converter Issues

I bought this converter on eBay to get my Dreamcast plugged into my new TV which does not have VGA input. All worked really well during the first fortnight of usage.

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4+ weeks into usage saw really bad performance from the device: screen distortion, black screens, incorrect resolutions and really crappy sound.

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Wiggling plugs had minimal effect, so it was time to pop it open. There isn't much to these things as it's all SMD and on a single board. I couldn't see any (overly) bad soldering or problem spots, so I guessed it would be heat causing the issues.

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I improvised a makeshift heatsink and the device started operating perfectly once more.

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It actually occurred to me that, since I was powering the device off the TV's USB port, the device had been powered up each time the TV was on; not just when the Dreamcast was on. I assume these things just aren't built rugged enough to be used 100% of the time?

Anyway... I can only recommend to all that you pop open your devices and put heatsinks inside them for stable usage!

28Mar/170

Javascript numbers with leading zeroes

Here is yet another public service announcement. I've recently been coding times for this post to track train timetables. Whilst doing so, I had the times in my array fully padded out to make everything easier to read.

i.e. for the southbound passenger timetable, I had the following:

var southbound_pax = [
    0530,0611,0633,0703,0714,0725,0733,0743,0752,0808,0823,
    0830,0841,0859,0917,0928,0944,1006,1029,1053,1109,1128,
    1148,1209,1230,1251,1309,1327,1348,1409,1427,1448,1512,
    1532,1550,1607,1618,1631,1651,1709,1726,1737,1754,1808,
    1818,1831,1844,1902,1915,1925,1937,1955,2014,2029,2050,
    2102,2121,2143,2208,2227,2255,2349
];

All of my testing had been done after 10am, so everything worked fine. This morning I get in and check the timings and it's all really wrong. I whipped up a quick test as I'd seen strange values in the arrays.

> var number_array = [0000, 0001, 0002, 0003, 0004, 0005, 0006, 0007, 0008, 0009, 0010, 0011, 0012];

> number_array
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 8, 9, 10]

Wait, what?... we're good until 0009. Then it goes nuts? A heavy bit of googling produced this warning on w3schools:

Never write a number with a leading zero (like 07).
Some JavaScript versions interpret numbers as octal if they are written with a leading zero.

Ohh.... riiiight... some... Did anyone else know of this feature?
Effectively, if it's octal, then 0009 should throw an error, right? Not just silently work and then flip back to '8' at 0010. Grrr...

7Mar/170

Burning M27C256B EPROMs with a Willem

This is another public service announcement. I've just wasted around 3 weeks trying to burn an EPROM which shouldn't've taken more than 1 minute. I purchased a Willem Parallel Port 5.0 PCB burner from eBay (cheap, I know) and although I could happily read chips, I couldn't write them.

The settings were correctly configured for the M27C256B chips. You need 6.2v to write and 12.75v external. This means you can't use the USB to power. This PCB 5.0 is dual power, so it should've selected the correct source.

Every time I tried to burn I got the following error: Error at 0x000000 chip = 0xFF buffer = 0x58. Note that all three of those values would change, a lot. 0x24 and 0x46 were frequently seen yelling at me.

eprom burner

Turns out that the 'latest and greatest' version of the software doesn't select the correct power source. Downgrading to 0.97ja (as per the screenshot above works fine.)

So if you're getting the errors as I was above, then use the 'alternate' version that should be on the driver CD that you were provided with.

4Dec/160

Virtual Box vs. Hyper-V (Visual Studio Android Emulator)

I've had Virtual Box running for ages. I use it for experimenting... I also use it to host VPN'd OS'. The whole concept of having applications and OS' fixed into a container is fantastic.

I also dabble with Smart-phone development; usually using a Macintosh or Android Studio on Windows. I recently became aware that Visual Studio Community 2015 comes with the opportunity to code Android/iOS apps via Xamarin.

I've attempted Xamarin before, but never built anything productive. This was years ago and have since forgotten about it. Seeing this option in VS meant that MS were somehow backing it and I therefore took the plunge.

Installing it was fine and building a sample 'WebView' application harmless. It even ran successfully in the emulator!

VirtualBox Conflict

Later in the day, I attempted to boot up my trusty VM to acquire a few things. I was greeted with the error that VT-x was not available. I attempted to re-configure the machine, but the Acceleration tab was disabled as Virtual Box could not actually find any acceleration to use.

It turns out that installing the Android Emulator for VS also installed Hyper-V Virtualisation. On any windows machine, only one Virtualisation manager can be installed and VirtualBox is not compatible with Hyper-V! There's a blog post here of someone asking the same questions.

I have found one blog post by Scott Hanselman that tells you how to 'multi-boot' into Windows where Hyper-V is disabled, but then you cannot run your Android Emulator. This post was actually from January in 2014! I'm surprised I've only just hit this issue.

It turns out that VirtualBox simply cannot work with Hyper-V. I'm not sure if the Android Emulator can work without it.

I attempted a switch to VMWare only to find that it is also not compatible with Hyper-V! At least it presents you with an appropriate message.

The Answer

The solution to all of this is to use the Hyper-V Manager which is installed as part of Hyper-V and create virtual machines from there. I haven't done this yet, but am not expecting too many issues.

25Oct/160

Creating a bootable DOS HDD without a boot device

I've come across this problem twice now. Both times it has been with older 'subnotebooks' which have no internal removable media and don't have the ability to boot from external drives. You also may just not have the ability to create a bootable floppy disk.

DSC06858

The problem also occurs when you have a harddisk, a USB to IDE converter and you want to make a bootable DOS partition on it. This can be done with USB keys, but HDDs, when attached to the USB bus, appear differently and most tools wont want to work with larger drives.

Using a virtual solution

Most emulators allow 'direct disk' access to physical drives attached to your PC. This can be a godsend, or can be seriously dangerous! I've tried a few now, and I'm a total fan of VMWare. Both DOSBOX and Virtual Box failed me.

DOSBOX got very close... I created a partition using diskpart in Windows 10 and then mounted the new drive as c in DOSBOX. I then mounted a DOS 6.22 disk image and tried to run the fdisk/sys/format commands, which all reported Incorrect DOS version. Booting DOSBOX with the floppy image resulted in not being able to access the HDD at all.

Virtual Box, with a lot of trickery, allowed direct physical access to the HDD. Unfortunately, the format and fdisk commands failed miserably with out of space (or other random) errors.

Preparing your disk with VMWare

Find a suitable version of VMWare Workstation and create a new virtual machine. It doesn't need to be high spec; give it 64mb RAM and no storage. Attach a floppy image (grab one from AllBootDisks). Next, go to Disk Management in Windows and work out your drive number. You can see below that I want drive number 3.

diskman

Once you've got this, you can configure a new storage device in your new virtual machine.

set-phys-1 set-phys-2 set-phys-3

set-phys-4 set-phys-5

If you chose Entire Disk then you'll be able to do the whole lot, regardless of the drive state, with VMWare. Otherwise, choosing Individual Partition will mean that you'll need to partition the drive somewhere else first.

98se-boot-disk fdisk sys

Once you're booted, you should be at a DOS prompt with all the tools you'll need. Run fdisk first and create your partitions. Make sure you set one to active!

Reboot the machine at this point, just to make sure all settings stick. Once back in, run fdisk /mbr for good measure. This will properly re-create the MS-DOS Master Boot Record that'll allow your BIOS to find your active boot partition.

Now that you've got a valid partition, run a format c:/s to format C as FAT and transfer system files to make it entirely bootable. Give the partition a label when it asks.

Copy Windows Setup Files

Grab a copy of your favourite windows from WinWorld. This particular laptop was 'built for Millenium'... hah... so I retrieved that ISO. I loved the screenshots!

winme-winworld

The best thing to do at this point (and the whole reason why we're here) is to copy over an entire Windows setup folder to the disk. This means that setup will be really quick and, down the track, you'll always have setup files handy. Remember how many times WFW311 used to ask for the network disk? Even if you were just changing IP configuration?

Note that the copying of the Windows Setup folder can be done outside of an emulator. The proviso here is that your host can read the format of the newly partitioned drive. Once copied, cleanly unmount the disk and get it back into the target machine.

If you get to a DOS Prompt, then you should only have to change to the windows setup folder and then run setup.exe.

6Oct/160

Japanese Medical Massage Chair

I could not resist going back for this item. Not only was it an antique, it was also a random Japanese item from the early 60s which had somehow made its way to Melbourne.

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Hah, it's crazy. Could it be the first edition of those chairs you put coins in at the airport.

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I have more information on that sticker above here. This was the only link with a similar chair. I wonder if I'll ever find the exact details? The shop owner told me that it was sold as-is. The cord was missing a real plug and it had never been electrically tested. I didn't mind at all... I mean... how difficult could the internals really be?

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Getting it going...

The mechanics seemed in very good working order. I applied a little more grease just to ease the friction further. The internals showed very simple wiring: the mains was fed into a double-pole double-throw switch which allowed speed control. There was a capacitor which seems to be an induction-motor capacitor to facility motor start. I must admit that it won't spin up on the low speed without a rolling start. I'll look in to replacing this.

I was initially going to find a replacement engine and overhaul the guts to 240v, but then realised that there were pretty cheap transformers that could cope with the wattage. One of these arrived from Sydney in no time at all!

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You can see that the cable it was supplied with was junk. This was removed pretty quickly and replaced with a USA power cord found at Jaycar. Their site says they are out of stock everywhere, but the Melbourne City store had 100s. I used a terminal block to hook it up internally and the cable worked perfectly.

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And, just to see it in action:

The rest is history... the chair just worked. 60 years later? Not too bad at all.. the massage it gives is great too!

4Oct/160

Remove batteries from unused electronics!

Recently, on one of my weekend visit-a-new-area-of-melbourne trips, I ventured into a thrift shop and stumbled across a wireless keyboard/mouse combination from Logitec. Usually I wouldn't look twice at the combo, but this time I did as I saw that it had PS/2 connectors at the other end!

My 386 was on its way, so this keyboard would be a perfect complement. I don't often go for wireless input devices as I'm not a fan of battery replacement, but I do remember that a wireless mouse from a previous company worked for around 6 months before showing the haywire symptoms of a dying battery.

Getting it home, I found that the keyboard was void of batteries. I was happy with this, as I didn't want to see anything corroded in there. Unfortunately, this wasn't the same for the mouse. The previous owner had left two cheap AAA batteries in there and one had failed.

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I pulled it apart straight away to assess the damage. Most of it was on the actual plate that runs into the battery chamber... but the corrosion had edged its way to the PCB also. Fortunately, on a redundant track. I quickly cleaned this off with alcohol wipes and a bit of scrubbing.

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The next trick was to fashion two new plates. I'd recently been dismantling a satellite decoder and this had a lot of RF shielding. One of these metal shields came in handy.

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A bit of soldering and some thick legs off a few power diodes and I had two new plates in and new batteries connected!

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This is one of the smoothest mice I've ever used, in Windows for Workgroups anyway!

2Oct/160

Random New Acquisition

I would've really loved to have been told the story behind this... Who would bother importing it to Australia? No real idea as it was in an antique store from an estate. Someone must've enjoyed the technology during the last war and taken it home with them?

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And the text version:

電気マッサージ器

型式認可 91-7948 厚生省認可 47B-371
定格電圧 100V 定格周波数 50/60Hz
定格消費電力 4P 150/125W 6P 125/100W
定格時間 30分 製造番号 721 0280
製造者名 株式会社 日本医療電機研究所

100v will mean a new motor or a step-down transformer that can handle the wattage. Stay tuned... (actually, don't Just browse here to see what it is!)

24Jun/160

Commodore 64: Fixing RS-232 Serial Limitations

This is going to be a bit of a rant, so I apologise in advance. I have just spent a good 75 hours getting the C64 to talk to an Arduino via RS-232 and each step of the way has been painful. Initially, communications were sorted and data made it across to the Arduino. All wasn't as it should be as I realised that the character mappings (PETSCII vs ASCII) meant that the data had to be translated. Once that was sorted, it was a matter of sending data back. Again, character mappings were required. Past this, I then wanted to send 64-bits of raw data. Not characters, but 8-bits-to-a-byte raw data as I wanted up to 64 sensors and therefore only 8 bytes to transmit this. Turns out that the C64 is hard-coded to transmute the serial value zero to something else...

Diagnosing the issue

I'd already built up a large-ish application on the C64 for controlling the trains. There was also a large amount of code on the Arduino side. Due to this, any support libraries or includes or other interrupt-hacking routines could've been interjecting and mangling data. After a lot of to-ing and fro-ing, compiling on windows and switching to SD card... I got jack of the speed of which I was able to debug on real hardware.

Fortunately, VICE came to my rescue. Not only does it have a debugger, but it also emulates the RS-232 User Port Serial and shit... it even reproduced the error! Let me show you how to set that up...

Configuring VICE's User Port Serial

rs232-userport-settingsOpen VICE and choose Settings -> Catridge/IO Settings -> RS232 userport settings.... Enable the RS232 userport emulation, leave it as device 1 and set the baud rate to 2400. Hit OK.

rs232-settingsBack to Settings -> RS232 settings.... We want to edit RS232 device 1. Fill in the text box with the relevant IP and port of the machine you wish to communicate with. If you're going to use my TCP server below, then enter 127.0.0.1:25232.

Close VICE. Next time you open it, VICE will attempt to connect to a TCP Server listening on your localhost IP on port 25232. You can configure this to whatever you want, but we are going to use the default. VICE will then treat the connection as RS-232 and provide any data received to the internal C64 user port. It will also send out any data sent to the user port via this channel.

Now that we're done with the settings, we need to give it something to connect to.

TCP Server in C#

Download the code here. I've rigged up a very simple C# TCP server for VICE to connect to. The TCP server must always be loaded first, otherwise VICE will continue silently and never send out any data. The code is also overly-primitive and, upon closing VICE, the TCP server will need to be restarted prior to starting another instance of VICE.

simple-tcp-console

Once running, you can use the 1-8 keys to set the bits of the byte to be sent. Alternatively, pressing any keys of the alphabet will set the byte to that letter in ASCII.

Finally, hitting Enter will transmit the byte.

C64 RS-232 Serial Test Program

Grab the Serial Test Application here that I wrote to test the RS-232 serial port on the C64 using Johan's driver. There's a batch file in there that you can use to run the program. Just make sure it knows where VICE is.

Make sure the TCP Server is loaded first, then run the batch program. It's set to auto-start the binary. If this doesn't work, then you can open VICE and via Settings -> Peripheral Settings... configure the directory where the binary is. You can then LOAD it as per usual.

peripheral-settings

Once loaded, you'll be in the app. It's pretty straightforward and will just print out the data that has been received.

c64-serial-app

Make sure that the TCP Server has shown that the connection has been established. You can now press the keys as per the instructions above on the TCP Server and send data. At the bottom is a timer and a number of bytes received. As each byte comes in, it'll be displayed up the top. It'll also be numerically represented down below, next to in:, above the clock.

At this point, type random letters from the alphabet and send them to the C64. You'll note that lowercase get translated to uppercase thanks to the ASCII to PETSCII translation. Tinker with the 1-8 keys to set the relevant bits in the byte to send and then hit enter. Watch that 1 = 1, 2 = 2, etc... until you try to send a raw zero... bugger.

Debugging the problem

Ok, we've now worked out that, even in the land of emulation, sending a zero to the RS-232 serial port on the C64 produces an 0x0d. This rules out the 'client'... both the Arduino and my TCP Server send raw zeroes and both VICE and a real C64 render the wrong character once received. From here, it could be the custom driver, the cc65 support libraries or something much more evil.

Debugging on real hardware is something I'm scared of... I'm so used to multiple windows and multi-tasking that I'd like to do it in a more comfortable environment. Thankfully VICE has a monitor that can help us. Open this up via the File menu and prepare to delve into the land of assembler! Note that, when open, the C64 emulation is paused.

vice-monitor

Once the emulator and application are loaded, choose View -> Disassembly Window. You'll get a little window showing the entire memory of the emulated C64, disassembled. This means that VICE, with it's knowledge of C64 6502 CPU op-codes, has translated the raw memory into known commands. Fortunately, it also has information on the mapping of the memory and therefore does a very good job of this translation. Unfortunately, there is no search command... so we will need to scour over this to find what we are looking for.

What are we looking for?

The million-dollar question. The serial test app that we've compiled for the C64 (and executed in VICE) is based on the sample code by Johan. It also includes his 2400-baud serial driver. Looking at his source code, we can see the routines that are called when we call the ser_get function from our main loop. If you browse over to his source, you'll find the relevant lines in driver/c64-up2400.s.

GET:   
        ldx #2
        jsr CHKIN
        jsr rshavedata
        beq GET_NO_DATA
        jsr BASIN
        ldx #$00
        sta (ptr1,x)
        jsr CLRCH 
        lda #<SER_ERR_OK
        tax 
        rts

vice-disassemblyThe snippet above was copied on the 24th of June, 2016. This code has hopefully been updated by now, but what you see above is the function, as it was back at that time, which reads data in from the RS-232 Serial port. I can't fully explain each line, but what we can do is find this chunk of code in the disassembly window. Unfortunately, we'll be doing this by hand as I don't know a better method to search for it.

After a lot of scrolling... this code has been found in memory location $238A. ldx #2 is seen as LDX #$02. The further jumps are visible, but their happy names are gone. Instead we see the memory addresses of each of those functions. You can see that I've also clicked the row in question. This sets a breakpoint, represented as a red highlight on the row.

Triggering the debugger

From here, we can actually close the debugger. Make sure that the red row is set prior to closing the main Monitor window. If you just did this, then you'll find that the debugger window popped back up straight away and now our red breakpoint is a lovely shade of teal. Teal? What happened to Red? In the disassembly list, a blue line indicates the location of the next line to be executed. Ours is teal because it's a set breakpoint AND it's the next line to execute. If you're bored, click the line and it'll turn blue. Click it again and it should return to teal.

Ok, we've triggered it... but why? No data was sent down the channel! It turns out that, if you look at the source above, there's a hint on the line with GET_NO_DATA. The ser_get is called from our code on each program loop; it returns a SER_ERR_NO_DATA when there is no data... so this line we've broken on is too early in the driver code. We really want to set a breakpoint at the first line executed when there is data.

So step through the code. To do this, press the 8th button on the toolbar in the Monitor window. Press it a few more times and watch the execution. We're currently 'stepping over' functions; the two JSRs might well send the program counter off into other parts of memory and execute code, but we don't care. Once you're on the BEQ GET_NO_DATA line, press it again. Note that we now jump down to the location of GET_NO_DATA and exit out. We can assume that this jump is the significant point where, when data exists, the execution continues straight through and does not jump.

debugger-at-char-received

Now that we know where this junction is, we want to clear our previous breakpoint and set one on the line directly after BEQ. Set the breakpoint and close the Monitor. It should not pop back up this time.

Viewing the data coming in via Serial

Ok, we've set our breakpoint in the driver and it hasn't triggered yet; let's hope it does when data is received. To test this theory, we'll need to use the TCP Server from above. If it's not already running, close VICE first and then start the Server. You need to have the TCP Server running prior to VICE for the connection to be correctly established. Once everything is running, ensure that the server has reported that the connection is established. Confirm your breakpoint is still in place; VICE doesn't save these, so you'll need to go hunting again if you lost the position. Once everything is configured, make sure you close the Monitor window to allow the C64 emulation to proceed. When the Monitor window is open, the CPU emulation is halted!

Once ready, focus on the TCP Server window and press the a key. Make sure it reports back that the byte is set to 97, which is ASCII. Press the enter key and you should trigger the breakpoint in VICE.

Ok, we've got it, our breakpoint was hit and we presumably have data somewhere? Our breakpoint is actually on a JSR through to the address $FFCF. At this point in time, this address is unfamiliar. All our previous driver code has been around the $2300 mark. Due to this, we're going to step over it. The next call is an LDA which uses a pointer + offset to load a value into register A. Stepping over this, we see the following in the Monitor window:

(C:$2394) n
.C:2397  A2 00       LDX #$00       - A:61 X:03 Y:00 SP:f2 ..-.....    6728381

Interesting... A:61 hey? That's the ASCII HEX value for a lower-case a! So there it is, the value has come through and we can see it in memory. You can close the debugger now and play around with data on the TCP server to see how it arrives on the C64.

Note that as soon as you try to send a zero from the TCP Server, it'll appear as an 0x0d. At this point, we've honed in on the location where the char is read in, but we don't know what code is hosted up in the $FF00 range?

C64 Memory Mapping

Time to go deeper. Thank god we're working on a seriously old system that has been thoroughly documented. You'll find the memory map of the Commodore 64 here. If you scroll down the page, you'll find that the area in question contains the Kernal (Kernel?). At this point... we might as well retire.

Retire? Yes. The KERNAL is ROM, you know... READ-ONLY MEMORY. It's the raw system code burnt onto chips on the motherboard and it is a fixed entity. Those bytes can't be hacked... anything we try to do will require reproduction of kernal commands in the 'user' area. Should we try this? Sure... but first it'd be nice to know what's going on.

C64 Kernal Disassembly

Again, thanks to the age of this system, there's a full disassembly of the C64 Kernal here. We know that we're jumping in to location $FFCF, so browse down to that area.

FFCF   6C 24 03   JMP ($0324)   ; (F157) input char on current device

Oh look, it's just another JMP. Fortunately it's commented and we know to browse through to $F157. Now we are in murky waters... not many comments here. We get a heading of ; input a character, but then not much else. The assembly, to the naked eye, looks like a switch statement. It seems to be going through checking which device to read from. In our case, we can actually step through it in the debugger. If you step into the JSR #$FFCF then you'll be able to watch it jump as you send in characters from the TCP Server.

The basic trail jumps through: $FFCF -> $F157 -> $F166 -> $F173 -> $F1B8 (a.k.a. read a byte from RS-232 bus) via F177. At $F1BD, there's a comparison of the incoming byte to 0x00. If there's no match, then the code jumps out to $F1B3 and returns the value. If there is a zero, then the following occurs:

F1C1   AD 97 02   LDA $0297
F1C4   29 60      AND #$60
F1C6   D0 E9      BNE $F1B1

If the AND fails to compare, then the jump happens at $F1C6 to $F1B1. Looking at $F1B1 made me cry. The code implicitly inserts an 0x0d, overwriting the byte that was read into the buffer and then returns it.

I don't quite know what the LDA from $0297 is and why it is AND'd with #$60. I'm sure there's some RFC or some prehistoric rule back in the late 1980s that said if a modem or other serial device returned a zero, then it actually meant it to be a carriage return. Maybe it was a BBS thing? I'll continue digging and attempt to comment this area of code, but for now... we know that it's futile. The KERNAL ROM is fighting us and thinks it knows better!

A valid workaround

Righto... what do we do here? I initially thought it was a complete loss and gave up. Further Sapporo made me realise that this call was made from our custom driver. What if we specifically mention that our custom driver is built to handle 'zero' byte data and implement a work-around? If we copy out the code from the Kernal and re-produce it in the driver, then we can effectively resolve this (I wont say bug, I'm sure they had their reasons!) issue.

So, the trick here is to grab the portion of code from the full disassembly of the C64 Kernal and build it into a function in Johan's driver.

We know the entry point is $FFCF. This is a JMP to the switch statement which chooses the device. We know that this is the RS-232 driver, so we can skip that part and copy the code from $F1B8 to $F1C8. I've pasted this in below.

; read a byte from RS-232 bus

F1B8   20 4E F1   JSR $F14E
F1BB   B0 F7      BCS $F1B4
F1BD   C9 00      CMP #$00
F1BF   D0 F2      BNE $F1B3
F1C1   AD 97 02   LDA $0297
F1C4   29 60      AND #$60
F1C6   D0 E9      BNE $F1B1
F1C8   F0 EE      BEQ $F1B8

That CMP #$00 is the pain. Let's just jump to $F1B3 all the time. Actually... $F1B3 is just CLC and RTS. Let's just write that. We also can't directly BCS to $F1B4, so we'll need to JSR to a closer function and then call JMP. If we JMP directly then we'll lose our position in the stack.

F1B8   20 4E F1   JSR $F14E
F1BB   B0 F7      BCS $F1B4   ;re-write this to a BCS and JMP
...    ...        CLC
...    ...        RTS

With my patch above, I've removed (what seems to be) a re-try loop in the code. If it falls all the way through to $F1C8 then it returns to $F1B8 and tries to read a character again. I haven't seen this state occur in real life, but I'll keep an eye out and try and work out when this actually occurs. It seems that the AND #$60 must check for an error state which I'm yet to encounter.

I don't actually know the assembled opcodes off-hand. We will write this as standard assembly into the c64-up2400.S driver source file and then it'll write the opcodes on compilation. So, from line 139 we slap in:

;----------------------------------------------------------------------------
; OTHERFUNC: Shortcut to Kernal code
;

OTHERFUNC:
		jmp $F1B4
		
;----------------------------------------------------------------------------
; OURBASIN: This is a minimised call to get the character from the buffer.
; The Kernal code does not allow zero bytes (0x00)... this does.
;

OURBASIN:
		jsr $F14E
		bcs OTHERFUNC
		clc
		rts
		
;----------------------------------------------------------------------------
; GET: Will fetch a character from the receive buffer and store it into the
; variable pointer to by ptr1. If no data is available, SER_ERR_NO_DATA is
; return.
;

GET:   
        ldx #2
        jsr CHKIN
        jsr rshavedata
        beq GET_NO_DATA
        jsr OURBASIN
        ldx #$00
        sta (ptr1,x)
        jsr CLRCH 
        lda #<SER_ERR_OK
        tax 
        rts

I'll give the kernal function a real name soon. Right now the basic point is that we write our own BASIN function that is just a tiny subset of the greater procedure and then skip the part where it inserts that shitty little 0x0d.

it-worked

Either way... compiling this (see notes on that here) saw the bloody thing work! I'm going to get in touch with Johan now and determine what needs to be tidied up to get this trick included in the trunk.

That was fun!

20Jun/160

Skype now has chatbots…

Seems to be all the rage, of late, adding bots... Facebook has done it, so Skype just has to follow along? There's a new icon, top-right of the main window that looks like a happy computer. Next time you're sad and lonely, click it and choose a bot to talk to...

I wasn't... I was happy and devious... and so I chose the CaptionBot. Supposedly it can 'caption' any 'image' you throw at it... What would a devious mind choose to send?

SkypeCaptionBot

Bravo, old chap! Two-outta-three ain't bad.