Search found 146 matches

by JonB
03 May 2021 16:02
Forum: HARDWARE
Topic: MTX 512 Black screen (of death?)
Replies: 27
Views: 21552

Re: MTX 512 Black screen (of death?)

So.. we can see that the only lines that are working are A0-A5 judging by the pattern in the ROM dump. I got the probe out and found that pins 2 and 3 were not connected. Guess what?

It's all working now.
It's all working now.
IMG_8006.jpg (100.91 KiB) Viewed 6472 times

What a Dibley.

That's right, I'd bent pins 1,2 and 3 when I put the ROMS back in after selling the Rememorizer. Pin 1 was making contact I think.
That's right, I'd bent pins 1,2 and 3 when I put the ROMS back in after selling the Rememorizer. Pin 1 was making contact I think.
IMG_8005.jpg (84.26 KiB) Viewed 6472 times



Thanks for your help, Dave and Martin!
by JonB
03 May 2021 11:23
Forum: HARDWARE
Topic: MTX 512 Black screen (of death?)
Replies: 27
Views: 21552

Re: MTX 512 Black screen (of death?)

It's a work of art inside.
IMG_8003.jpg
IMG_8003.jpg (958.19 KiB) Viewed 6480 times
by JonB
03 May 2021 11:03
Forum: HARDWARE
Topic: MTX 512 Black screen (of death?)
Replies: 27
Views: 21552

Re: MTX 512 Black screen (of death?)

Not as useful as a Z80 ICE, but it can show timing information too. Also handles 68000 (with a different adapter box and clip). Here's a random shot of some timing captures. IMG_8002.jpg It's very old and quite rare - there are no documents about it anywhere on the Internet, so you have to work out ...
by JonB
03 May 2021 10:43
Forum: HARDWARE
Topic: MTX 512 Black screen (of death?)
Replies: 27
Views: 21552

Re: MTX 512 Black screen (of death?)

Yes, it's an 06 with the red dot PAL. I've connected the Zicon up (what ablast from the past) and amazingly it is still working. :lol: IMG_8001.jpg I set it to trigger when the address line is 0000h, so it captures events from that point. Then applied power to the MTX. IMG_7999.jpg The Zicon reconst...
by JonB
03 May 2021 10:18
Forum: HARDWARE
Topic: MTX 512 Black screen (of death?)
Replies: 27
Views: 21552

Re: MTX 512 Black screen (of death?)

Super, thanks Dave There's a definite pattern in my ROM: OK ===> d 0 0000 F3 AF 21 00 40 C3 94 01-5E 23 56 23 C9 FF FF FF ..!.@...^#V#.... 0010 E3 F5 7E FE 40 C3 FA 06-C3 74 3B D7 2D 0A C9 00 ....@....t;.-... 0020 F3 AF 21 00 40 C3 94 01-5E 23 56 23 C9 FF FF FF ..!.@...^#V#.... 0030 E3 F5 7E FE 40 C...
by JonB
03 May 2021 10:05
Forum: HARDWARE
Topic: MTX 512 Black screen (of death?)
Replies: 27
Views: 21552

Re: MTX 512 Black screen (of death?)

That's jolly useful! Can I put the 8k ROM image directly in ROM A's slot and run the diagnostic tests without building a test board? Reading the thread it appears so. But you mention and adapter, so what is the schematic for it? And secondly, what types of ROM chip are acceptable to the MTX? And thi...
by JonB
02 May 2021 23:29
Forum: HARDWARE
Topic: MTX 512 Black screen (of death?)
Replies: 27
Views: 21552

Re: MTX 512 Black screen (of death?)

Thanks Martin So something seriously hokey is going on here.... :( .. or the ICE is duff (possible, I've had issues with it before). I have another truly ancient device that might prove it one way or another. A Zicon "logic analyser" which cna monitor the pins of the Z80 and capture its in...
by JonB
02 May 2021 15:37
Forum: HARDWARE
Topic: MTX 512 Black screen (of death?)
Replies: 27
Views: 21552

Re: MTX 512 Black screen (of death?)

No bent pins on the ROM chips. :( I've tried reseating them all but it's not made a difference. Is there a ROM disassembly anywhere? Looks like it's got a full memory map: OK ===> md 0000000000000000111111111111111122222222222222223333333333333333 0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123...
by JonB
02 May 2021 14:14
Forum: HARDWARE
Topic: MTX 512 Black screen (of death?)
Replies: 27
Views: 21552

Re: MTX 512 Black screen (of death?)

It's a 512. I think Andy gave me a PAL for the RS232 card which mine does not have. That went with the Rememorizer to Lardo Boffin. But I was wondering about the PAL and whether or not I changed it. I don't think so... how best to tell? Mine has a red label on it (like a disk). It looks the same as ...
by JonB
02 May 2021 13:22
Forum: HARDWARE
Topic: MTX 512 Black screen (of death?)
Replies: 27
Views: 21552

Re: MTX 512 Black screen (of death?)

It’s been so long since I did anything with this machine. The ROMs look to be fitted correctly. It’s a 4000-06 board. Looks like I’ll have to connect the Z80-ICE and check to see if there is any RAM error. Is the RAM all accessible when it boots, or does it switch? What I need is an initial memory m...