One of the PCBs I own had a dead SLAPSTIC, Atari’s custom protection chip used in several games of the time, which meant I just got a nice ROM error in test mode and a blank screen instead of the game. Some old 8 bit hacking and we have hopefully fixed the problem. Check out…
In normal mode, just had a blank screen. Enable test mode and you instead get an error message showing that the ROM test had failed (even though the rom itself checks out OK with correct content) This is because the custom Atari SLAPSTIC chip is not functioning correctly. It is used to page banks of…
After some experimenting with layouts / shipping and generally learning to use it, the Store is now live and ready to use. I’ve only put a few PCBs on there for the moment and until the next delivery there isn’t many of those available yet. More items will appear once I have finished sorting the…
I’ve updated the bill of materials for the Astrocade interface a little. Two items have been changed to have better descriptions and where people have let me know part numbers from Mouser or Digikey I have added them on.
Version 2.3 of the PCB has arrived, been assembled and tested … and it works without any wire patches! There is, however, one minor problem. I added some extra bits of screen print on the wrong side. This has now been fixed on the gerbers and any future boards will be correct, but I am…
I know it looks the same as the pictures from the Multigame connected to a galaxian PCB, but this time I updated the Galaxian core on the MiSTer to allow me to run the multigame on it. It should make testing things a lot quicker since the MiSTer is always connected and ready to go….
I thought that swopping the CPU in the cosmic core to allow me to do Cosmic Guerilla would be simple. How wrong was I … 16 bit vs 8 bit, different memory read write signals, different port handling, even the reset is different! Anyway, for the first time it actually shows something running on screen….
I have finished moving the remaining pages from the old Frontpage website over to WordPress and put some of the archive history back in. I did have to modify a few things to make it more ‘mobile’ friendly so all pages should be viewable on your phone. (a few require you to rotate your phone…
Information about Williams Make Trax game. PCB Screen Shots Pinouts If you are making a Jamma loom, then use the negative sync on pin R, as most monitors in Jamma cabinets appear to be set for this. The sync is taken from here, put through a 74LS04 inverter and back to pin F to generate…
Information about Midway Galaxian PCB Screen Shots Pinouts Connections for AC version shown in (BOLD) DIP switches
Totally dead, no screen display (blank white screen). For this I used the Fluke Z80-S2650 adapter to check out the ram and rom, and located two errors. The rom mapping was incorrect, with a large range of locations returning random values. Examining the board (since I have no schematics), all of the chip select lines meet up…
Altered Beast – Colours missing, no reds, other colours looked like diminished palette (like windows in 16 colours) – used test mode to perform ram test, and one ram chip identified as faulty (I10). Replaced this and red was back, but still reduced pallette. Looking at colour circuit, and it uses resistor arrays driven by I11…
On power up – black screen, no sign of life at all. I removed the 68000 CPU and fitted a socket, so I could use the Fluke on it. This revealed that the main program ram ($10C000-$10FFFF) was totally dead. Replacing the two ram chips IC25 and IC26 solved this problem. Board now started up,…
Screen filled with coloured lines, unstable, no sync (see above) – check clock signals from horizontal and vertical scan generators (74161’s at 2R,2S,3R,3S) – no signal feeding into pin 2 of horizontal generators. Follow trace back to 7474 at 3N, signal going in, nothing coming out – replace chip and screen display back to normal….
6 Slot – Memory test on power up giving error Address Write Read 00008000 5555 55FF Checking with Mame, the memory chips in question were only small, so looking at the board revealed two DIL 5814’s. Chip select signals to these were toggling as expected, so I needed to identify which ram chip was which….
Blank screen, Blanking line to output colour proms always enabled. Trace back to 74161 in timing circuit – output stuck, input clock all look OK – replace chip and picture appears. Blue video only – The video lines are controlled by three transistors near the edge connector, checking these revealed that 2 were not giving…
Boots up, and plays, but incorrect sprites – most noticeable little bug changes into ‘END’ at one point. Check 74ls138 at 8n, controlling graphics banking, and pins strobing. Replace chip and now uses correct sprites. Quiet missile sound and explosion sound. Both of these effects use the op-amp chip, LM324 at 7T. Replace this chip…
The board originally failed to get into the game, instead resetting just after drawing the ‘MISSILE COMMAND’ logo. Test mode faired a little better, managing to report RAM OK, MAP OK and ROM OK before resetting. Ram and Rom checked out OK using the Fluke. Measuring various CPU signals revealed that the interrupt seemed very…
Boot up with garbage, quickly clears screen and then nothing. Used Fluke with Z80 pod – read rom OK, and write ram OK, but timeout reading any Ram location. Check fluke status and ‘wait’ always set. Check pin 24 of Z80– stuck low, trace back through 7H,7C,6C1 to 6B1 pin 2 – always low, although…
No picture, Hole blown through LOPT. Had problems tracking down replacement – little tip given to me by Hantarex engineer – you can use the LOPT from an MTC9000 as long as you cut pin 2 off. (If you leave it connected, you will get a direct short to GND)
I managed to complete another core for the MiSTer today, been a while as I needed to get the two PCB’s working enough to sample the sounds. But all of the games from Mame’s Universal Cosmic driver that use a Z80 are now on there. Cosmic Alien, Devil Zone, Magical Spot, No Mans Land and…
I was looking for some information on arcade monitors, specifically listings of capacitors needed for Capacitor Kits, and everything I found seemed to be in the way-back archive rather than on current sites. So duly reformatted the information that I found, started adding links to manuals and schematics, where I have them, and of course…
If you have the galaxian multi game, then I have a beta to test – Clean Sweep finally makes it in there. It should work with high scores and dip settings although it hasn’t been extensively tested. Grab the rom images here
Following on from Astrocade hardware, I thought I would like to do a core as near as possible from scratch. So apart from using the Z80 from opencores, and basing the timing code on that used in the Pacman core, I went from the Crazy Balloon schematics to produce a complete core for it. Where…
Well, what a weird year it has been so far. I’ve been learning to code in VHDL and Verilog on the MiSTer platform. The first task was one I have wanted to do since I bought an FPGA Replay was to take the existing Bally Arcadia console core, add in the necessary extra ram, pattern…
New game on the way for the multigame, a conversion of Clean Sweep from the Vectrex. I have it running on standard galaxian hardware, just need to do some address and control changes to make it compatible with the Multigame setup.
I heard from a user about a problem with the signed Xeltec drivers. So in case you are having the same problem :- My new PC has windows 10 installed as UEFI. Installing it that way enables secure boot by default and saves the default keys to your motherboard. Secure boot adds another layer of…
Finally finished building my new test rig! Hopefully get the rest of the test gear setup again and start fixing some boards.
Aaron mentioned that Amidar in the multigame always runs in cocktail mode, no matter what settings you selected. I am amazed no-one else had noticed this since it has been like it since the start! Anyway, for the one person who actually plays Amidar in two player mode, I have now fixed the bug. Grab…
Phil, posted some code to implement attract mode when in freeplay for Moon Cresta. The version used in the multigame (bootleg on galaxian hardware) is close enough that it works with some minor modifications. I also fixed the ‘Freeplay’ message whilst I was in there. He has also posted code for scramble which I will…
Slight update to the PinDMD3 driver, it now uses a 1×8 pixel colour mask to avoid ‘power of 2 texture’ problems. New cab delivered, so something else to keep me occupied on those winter nights – Crazy Climber!
The new driver for PinDMD3 has been completed and is now available for download here. By default it works exactly the same as the ‘normal’ FPInterface and converts images and font data to DMD colour scales to display, however, add a decal with a special texture to the table and it proceeds to send all background…
A fellow collector, Phil, posted some code to implement attract mode when in freeplay for Galaxian on one of the forums I frequent, so I have adapted the code to work with Galaxian, Galaxian Part X and Moon Alien within the multigame. I have also fixed a long standing coin counter bug just in case…