Search found 149 matches

by Bill B
10 Jun 2019 08:34
Forum: GENERAL DISCUSSIONS
Topic: [MAME] Emulating the MTX
Replies: 19
Views: 3375

Re: [MAME] Emulating the MTX

I have also implemented loading software from WAV files in MEMU http://primrosebank.net/computers/rpi/projects/memupi/memupi.htm . One issue with this has been noticed. As you probably know, the sound of the tape loading does not come directly from the tape, but is faked using the sound chip. Someti...
by Bill B
10 May 2019 21:47
Forum: HARDWARE
Topic: Resurrecting an MTX500.
Replies: 219
Views: 4697

Re: Resurrecting an MTX500.

"Z80 Applications", James W. Coffron. A good book in general. Taught me most of what I know about microprocessor interfacing.

I tried to upload a scan of the chapter but the file is too big :(

Edit: Found a Google link to a similar description here
by Bill B
10 May 2019 21:18
Forum: HARDWARE
Topic: Resurrecting an MTX500.
Replies: 219
Views: 4697

Re: Resurrecting an MTX500.

One of my Z80 hardware books recommends a test / debug method called "static stimulus testing". The idea is you remove the Z80 and replace it with switches and resistors. Then you can put any state you like on the buses and control lines, and check all the decoding logic. Much easier than trying to ...
by Bill B
23 Apr 2019 11:45
Forum: NEW HARDWARE
Topic: System test rom/Board
Replies: 26
Views: 946

Re: System test rom/Board

A few years back I had an idea for a slightly more complex test board, which would solve the display issue. If you pull the Z80 /BUSREQ pin low (which is on the edge connector) the Z80 stops and floats all the signals. It is then possible to probe all the hardware from outside. So my idea was a boar...
by Bill B
25 Mar 2019 16:21
Forum: PROGRAMMING
Topic: Relocating MTX Machine Code
Replies: 5
Views: 298

Re: Relocating MTX Machine Code

It occurs to me that the reason that MC on the MTX is always at the top of a program is that if you put it anywhere else, editing the Basic code usually moves the MC and invalidates all the addresses. Building upon the code above, it should be possible to write a routine to put at the top of a progr...
by Bill B
25 Mar 2019 16:07
Forum: PROGRAMMING
Topic: Relocating MTX Machine Code
Replies: 5
Views: 298

Relocating MTX Machine Code

This arose from a question Paul asked me. If writing a program containing mixed Basic and Machine Code, the first line of the program typically looks something like: 10 CODE 4007 RET ; Do nothing when executed 4008 JR ENCODE ; Jump table to M/C routines 400A JR DECODE This works fine when working on...
by Bill B
09 Feb 2019 15:47
Forum: GENERAL DISCUSSIONS
Topic: [MAME] Emulating the MTX
Replies: 19
Views: 3375

Re: [MAME] Emulating the MTX

F: is usually a RAM disk not a Silicon Disk. It uses the pages above 64K on the MTX. So you should see activity on the page port (0x00) not on the Silicon Disk I/O ports. SIDISC formats both RAM disk and Silicon disks.
by Bill B
01 Feb 2019 10:40
Forum: SOFTWARE
Topic: New tape cleaner tool
Replies: 36
Views: 2859

Re: New tape cleaner tool

At this point I retire from tape cleaning and move on to something else. Attached is the latest version of my program. It has some additional scanning modes. It also the ability to manually edit the pulses. To do so: Choose a scanning mode and parameters to do the best you can in interpreting the fi...
by Bill B
01 Feb 2019 10:26
Forum: SOFTWARE
Topic: New tape cleaner tool
Replies: 36
Views: 2859

Re: New tape cleaner tool

Patience.png A last one from me. I never managed to fully read the audio files for Patience. They have relatively large system variables blocks, in which I invariably drop bits. However I think I managed to read the Basic block (with some manual editing of the pulse train). I then turned this into ...
by Bill B
25 Jan 2019 21:05
Forum: SOFTWARE
Topic: New tape cleaner tool
Replies: 36
Views: 2859

Re: New tape cleaner tool

If is anybody else wants to have a play with TapeView, source code and compiled (Linux x86) version attached. It should be possible to compile for RPi (easy) or Windows (more work required), although I have not done so. Some cautions: The code is not well structured, it just grew. It is not commente...