Derek Andrews

Carlsson, thanks for sharing all this info. What exactly is that LCD you are running there? Is it a computer monitor or tv? What is its input format?

The datasheets look the same to me. My interpretation is that VPP could be held at 25V throughout the programming operation. Whether that is how your programmer works I don't know, but my guess is that is the simplest way to do it, so most likely. If you do make your own supply the only constraints are that VPP must not be applied without VCC being present and the absolute max value is 28V, though they spec it at Vcc +/- 0.6V. There is a thread here that may help: http://www.mcumall.com/forum/topic.asp?TOPIC_ID=8202 Someone reporting the exact same problem and finding that VPP is only 21V on that programmer.

Probably best to leave it alone then if you aren't confident. There are some extremely high voltages in a CRT TV. Or you could just leave the tv to me in your will With the tv off you could use a multimeter on its resistance range to see what you can find out about that pot, though without the circuit diagrams it's hard to be conclusive, but looking at the solder side of the board we see that the wiper is connected to one end of the track. That tells us the component is being used as a variable resistance rather than a potentiometer (a variable potential divider). https://en.wikipedia.org/wiki/Potentiometer If B5KX means its a 5k ohm device, put the meter on the lowest range above that, probably 10Kohm. Measure the resistance across the two outer connections and turn the control, but that does depend on external circuitry. Change the meter to a lower ohm range if necessary to get a more accurate reading. As you slowly turn the control you should get a smooth change in the meter reading (easier to see on an old analog meter with a needle than it is with a digital meter). If it is at all jerky or doesn't move at all then it is possible that the contact between the wiper and the resistance track is dirty. Let us know what you find and we can take it from there.

You could try putting a voltmeter on the wiper of the pot and see if it changes while you turn the knob. Try it on both dc and ac. If nothing happens on the lowest voltage range you can use, then suspect a faulty pot, desolder it and test it for resistance.

I have been using WinArcadia for a while now, primarily as a game development tool. I bought a Logitech F310 Gamepad to try playing some older games with it, but I am completely stumped about how to get the controls working properly. I have looked at all the settings on WinArcadia that I can find but nothing there seems to help. Some functions seem to work. The left joystick will move things around but pressing it down seems to reset the game which is beyond annoying. The Windows hardware settings don't seem to be much help either. I'm new to all these levels of complexity, and I'm probably overlooking something obvious, so any help would be appreciated.

They would have had to be shipping a lot of cartridges to cover the cost of mask programmed ROM's. We used EPROMs at Voltmace.

I am running Winarcadia 24.56 on Windows 10 and the built in 8550 and 8600 pongs seem to work ok. Do you have a binary for the 8500 from somewhere? The thing is, I'm surprised to see these on this emulator, as it is mainly a 2650 emulator.

Roli, if you do know who wrote that version of Flappy, please complement him/her on such honest documentation and pass this on to them. I hope it helps: " ;LODA,r1 YCOORDS,r3 ;DOESN'T F***ING WORK! WHY? Wenn du weißt, was ich hier falsch mache, sags mir! ;Dieser Frickelfix mit der Lookupkludge ist so ziemlich das hässlichste an Code, was ich je geschrieben habe ;(gut das stimmt nicht, aber ich habe meine Gründe für hässlichen Code) ;das Ergebnis ist jedenfalls als würde die Instruktion nicht existieren (bzw. ausgeNOPt)" OK, I only understand the bits in ALL CAPS. The problem there is that when you use indexed addressing on the 2650 the argument register defaults to, and can only be, r0. If they are using the same assembler as myself, it codes it up as if it were LODA,r0 YCOORDS,r3 or LODA YCOORDS,r3 and issues no warning. I learnt this the hard way too and took a long time to find the problem. So, in this bit of code where they are loading a sprite, they might think they are using r1 to transfer the data, but they aren't. It will assemble, it will work fine, but it will in fact be using r0 to transfer the data, and they probably wouldn't notice unless they had something important stored in r0 outside the loop;-) LODI,r3 $ff LOGOLOOP: LODA,r1 GFX_LOGO1,r3+ STRA,r1 SPRITE1,r3 LODA,r1 GFX_LOGO2,r3 STRA,r1 SPRITE2,r3 LODA,r1 GFX_LOGO3,r3 STRA,r1 SPRITE3,r3 COMI,r3 $09 BCTR,lt LOGOLOOP Just one more thing. Unless you need to load the sprite top-bottom in a hurry before the top bytes get displayed, it is slightly more efficient to do it bottom-up. The BRNR does away with the need for a COM instruction. lodi,r3 $0E loopIS: ;load sprite shapes and coords loda,r0 select1,r3- stra,r0 sprite1,r3 loda,r0 select2,r3 stra,r0 sprite2,r3 loda,r0 select3,r3 stra,r0 sprite3,r3 loda,r0 select4,r3 stra,r0 sprite4,r3 brnr,r3 loopIS

thanks. The Fairchild looks to have more direct access to video ram rather than relying on the capabilities and limitations of the Signetics PVI. Programming games for that machine would be a quite different proposition.

I don't know much about the Fairchild machine or recent releases for it. Are there any videos or screen shots of old and new games I could have a look at? The one I am working on I think will just use 4k ROM. One other game idea I have may need RAM, but as I'm working on an emulator anything goes,and I had figured that most will be running it on either console emulators or rom emulators so it wouldn't be a problem. I hadn't given much thought as to what to do with new games. Would people be interested in cartidges do you think? I'm not keen on investing in making cartridges as they are so easy to rip off these days.

My interest has been piqued. I have ideas for three new games and one is progressing reasonably well. I'm using WinArcadia for test and debug. When I am a little further on I will post a binary of progress to date and maybe someone with a rom emulator could try it out for me?

I have something very similar that I have written for the Interton family of games in Signetics 2650. A couple of enhancements though. I set up equates to make it easier to convert the music to code: midD equ $1A ; tones midE equ $17 midF equ $15 midG equ $13 midA equ $11 midB equ $0F silent equ 0 crotchet equ 12 ; durations minim equ 24 inter equ 3 musicend equ $ff ;stop 'inter' is a short pause I insert between notes. 'music end' is used by the subroutine to see when the tune has ended. It is also possible to pass the start address of the music data to the subroutine via an indirect RAM address. Thus I would have a standalone subroutine that simply needs the music code in a block of data with a 'musicend' byte to indicate its termination. This could be one of many tunes. Simply set the address of the block of music you want to play in to RAM and call the subroutine. This is what the music looks like: twinkle: db silent db inter db midD db crotchet db silent db inter db midD db crotchet db silent db inter db midA db crotchet ...... ... db minim db silent db musicend

I recently started using Winarcadia, and wonder what joysticks I can get that will plug into a PC? I am using it for Interton/Voltmace emulation and those sytems had analog joysticks with 12 button keypads. Is there anything out there that would do this?

Were any of the compatible systems made for the US market? I'm curious as to how well some of the code worked on the faster TV screen refresh rate of NTSC. I think Leapfrog may have been tricky as there was a lot of code that ran during each frame and I recall having some problems getting everything done in time.

Roli, interesting video, thanks for sharing. I like that someone is still writing for this system, and I will have to have a look in more detail at his source code for flappy bird. What was the name of some of those games on your video after Leapfrog? There were several that I hadn't seen. Maybe they never made it to the UK? Do you know who and where they were written? One looked like Defender. I was actually working on a version of that before I left Voltmace. There was another space invader type game that had diagonally firing lasers. I would be interested to learn how they achieved that.

Would love to, but I have no hardware at all. Not even a TV! And I guess it would have to be a hobby as monetizing it would be hard with all these ROM emulators around Maybe I should try and write an emulator for the whole system!

Thank you. I have attached some of the more finished parts - a few subroutines. snippet.txt

Is this the same as the MAME project that I keep coming across? I read here http://forums.bannister.org//ubbthreads.php?ubb=showflat&Number=103774&page=2that Leapfrog doesn't run very well on it. I tried joining that forum, to see if I could help, but still waiting for approval. Yes, will try and contact Mario.

Well, I had just got laid off from my first job after university when Voltmace were advertising for a programmer and I got the job. I had some 6800 microprocessor experience from my final year at uni, and had been programming ATE for Texas Instruments for a few years, so I guess that helped, but I had no knowledge of the 2650 or video game programming, so most of it was made up as I went along. It took a lot of experimentation to be sure I understood how the hardware operated. It was thirty five years ago, and my memory of it all is quite sketchy, but I have found the necessary datasheets and am making good progress with understanding the code. It's a bit messy; I think deliberately so to try and discourage anyone from trying to hack it! If only I had known! If I could figure out how to attach files to this board I would share what I have done with my documentation so far. I would appreciate feedback so I know what information people might like to see in it. Always happy to answer any questions you may have.

That is interesting. I am the programmer that created this code and am interested in taking a stroll down memory lane and try to document the code. So far I have downloaded the DASMx disassembler and eventually managed to get something output, though I have a feeling it could be better (it would be nice if it showed the hex code alongside) and I haven't gotten into trying to make better use of the sym file. So I am wondering if anyone here is familiar with that program and could help me out. Or maybe someone has already done a disassembly and/or tried to document the code?