exxos's Atari, Amiga & retro forum

Trollbra wrote: 19 Dec 2020 00:19 The game is Crownland : http://a8.fandal.cz/games.php?name=C&bu ... =&from=250

I check 64k and 128 bank with Sys-Check cartridge, it's ok !

Sys-Check currently checks only the 64 KB base memory. I didn´t find the time to make new firmwares yet, but it´s on my personal roadmap ;)

I would bet several bucks that your 2nd bank is defective. Your photo shows good Toshiba DRAMs in the first bank, but proud-to-fail Micron DRAMs in the second bank. The second bank is used for the 64 KB expanded memory mirrored in four banks of each 16 KB. Crownload uses extended memory for graphics, so I´m 99,9% sure, that the extended memory is bad.

Micron DRAMs are bastards. Sometimes one defective chip influences the next, but itself shows it´s bits okay. Mostly, when you run one of the extended memory test tools, you will get different results with every run. There´s only ONE reliable way to solve: Remove all eight Micro DRAMs and install new ones. Otherwise you will re-open the machine after a few weeks to change the next Micron DRAM.

Or install one of the cheap and reliable 512 KB expansions, because a lot of games need more than 64 KB extended memory.

Thanks for your answers, I try this. Ok for images orientation ! :)

Trollbra wrote: 19 Dec 2020 10:43 Thanks for your answers, I try this. Ok for images orientation ! :)

You need to fix this post https://www.exxosforum.co.uk/forum/viewt ... =30#p54774 you only get 24 hours to do edits.

tfhh wrote: 19 Dec 2020 10:06 Sys-Check currently checks only the 64 KB base memory. I didn´t find the time to make new firmwares yet, but it´s on my personal roadmap ;)

On 130XE too ? :?:

tfhh wrote: 19 Dec 2020 10:06 I would bet several bucks that your 2nd bank is defective. Your photo shows good Toshiba DRAMs in the first bank, but proud-to-fail Micron DRAMs in the second bank. The second bank is used for the 64 KB expanded memory mirrored in four banks of each 16 KB. Crownload uses extended memory for graphics, so I´m 99,9% sure, that the extended memory is bad.

Micron DRAMs are bastards. Sometimes one defective chip influences the next, but itself shows it´s bits okay. Mostly, when you run one of the extended memory test tools, you will get different results with every run. There´s only ONE reliable way to solve: Remove all eight Micro DRAMs and install new ones. Otherwise you will re-open the machine after a few weeks to change the next Micron DRAM.

Ok, I own any TMS4164-15NL, are they compatible with the first bank (42164-15) ?

tfhh wrote: 19 Dec 2020 10:06 Or install one of the cheap and reliable 512 KB expansions, because a lot of games need more than 64 KB extended memory.

if i'm sure RAM/MMU are the problem, why not... What expansion do you advise ?

Otherwise, I check Battlezone (5200) with 64k only (and MMU), there are any glitch toos (but not on all games, Blue Max works normally per example) !

Trollbra wrote: 19 Dec 2020 14:42Ok, I own any TMS4164-15NL, are they compatible with the first bank (42164-15) ?

By markings, they are ok, but these chips look suspicious to me. Like they were sanded and re-engraved. Do they come from Aliexpress?

I had similar glitches in my 800XL, and it was a faulty ANTIC chip (it was working correctly only when freezed using compressed "air").

tzok wrote: 19 Dec 2020 15:29 By markings, they are ok, but these chips look suspicious to me. Like they were sanded and re-engraved. Do they come from Aliexpress?

Yes... :?

Trollbra wrote: 19 Dec 2020 14:42 On 130XE too ? :?:

Yes. Currently only 64 KB base memory is checked. For testing extended memory several utilities are availible.

Trollbra wrote: 19 Dec 2020 14:42 Ok, I own any TMS4164-15NL, are they compatible with the first bank (42164-15) ?

They work fine!

Trollbra wrote: 19 Dec 2020 14:42 Otherwise, I check Battlezone (5200) with 64k only (and MMU), there are any glitch toos (but not on all games, Blue Max works normally per example) !

Sometimes defect RAMs in bank 2 can also influence the first bank with base memory, because nearly all signals are connected to both banks (RAS, Write_Enable, Memory Addresslines A0 to A7), only the CAS signals are different. So maybe here´s the issue.

But, also check how the game is started. There are a lot of bad file compressor ("cruncher") tools in the wild. In the early days, where disk space was expensive, such tools are used often. Sometimes they have several bugs, most common: not to zero out the memory used as buffer during decrunching. And when PMG (player-missile-graphics) are used in this area, you gut somethink like your picture shown. When in doubt, try the same game from some different sources.

I just checked extended memory with short test :
Other problem, games don't launch with SIO/SDrive Max ! :o

PS. I changed 6502 and ANTIC, the same...

I prefer this test for extended RAM:
https://satantronic.com/files/8bit/tools/XRAM0220.XEX

tzok wrote: 19 Dec 2020 22:58 I prefer this test for extended RAM:
https://satantronic.com/files/8bit/tools/XRAM0220.XEX

Thanks, I tried it but it freezes on this screen :
After reset :
After power off/on and relaunch XRAM :
There are any points on basic screen, like a grid...