Search found 325 matches

by stephen_usher
05 Jul 2023 10:44
Forum: PROGRAMMING
Topic: Sound Engine & Midi Music player for the MTX
Replies: 28
Views: 100893

Re: Sound Engine & Midi Music player for the MTX

Use the CTC in Timer mode, not Counter mode. It then uses the 4MHz system clock. A divide by 16 pre-scaler and a count of 8 will give a 31.25khz output. The DART will have to be operated in x1 clock mode. To operate the DART in x16 clock mode would require a 4MHz/8 data clock, which the CTC cannot ...
by stephen_usher
05 Jul 2023 10:43
Forum: PROGRAMMING
Topic: Sound Engine & Midi Music player for the MTX
Replies: 28
Views: 100893

Re: Sound Engine & Midi Music player for the MTX

Can't the Z80 DART on the serial board be persuaded to talk MIDI? If so then the Memotech could act as a MIDI instrument and record the data coming in. I believe that the usual voltages for MIDI are incompatible with RS232, so at least some level converters would be needed. However this is probably...
by stephen_usher
03 Jul 2023 20:22
Forum: PROGRAMMING
Topic: Sound Engine & Midi Music player for the MTX
Replies: 28
Views: 100893

Re: Sound Engine & Midi Music player for the MTX

Can't the Z80 DART on the serial board be persuaded to talk MIDI? If so then the Memotech could act as a MIDI instrument and record the data coming in.
by stephen_usher
23 May 2023 20:08
Forum: INTRODUCE YOURSELF
Topic: Just a quick introduction
Replies: 6
Views: 9412

Re: Just a quick introduction

I've already been helping via the Exxos forum. :-)

Once you have the MFX you just have to try Hextrain just to be wowed by the graphics (and the amazing "hack" used to make it possible).
by stephen_usher
16 Apr 2023 10:36
Forum: HARDWARE
Topic: GOTEK
Replies: 13
Views: 22792

Re: GOTEK

That FDX (and machine) both need a bit of a deep clean!
by stephen_usher
13 Apr 2023 20:28
Forum: HARDWARE
Topic: MTX printer cable needed -URGENT
Replies: 10
Views: 23471

Re: MTX printer cable needed -URGENT

Isn't it the same as the BBC Micro parallel printer cable? I'm pretty sure that it is.

http://www.gamebytes.co.uk/det/651/BBC- ... ter-Cable/
by stephen_usher
02 Apr 2023 23:59
Forum: HARDWARE
Topic: GOTEK
Replies: 13
Views: 22792

Re: GOTEK

HCT should be OK. They're only a little slower than TTL but use the same voltage triggering levels (approximately). 74LS244s are quite flaky at the best of times. I'm not sure if Memotech got somebad batches from TI but those and 273's seem to have been the chips which failed in my MTX500 in the lat...
by stephen_usher
02 Apr 2023 14:28
Forum: HARDWARE
Topic: GOTEK
Replies: 13
Views: 22792

Re: GOTEK

Were the original 74LS logic chips duff in some way?
by stephen_usher
20 Mar 2023 21:56
Forum: GENERAL DISCUSSIONS
Topic: The MTX on Youtube
Replies: 2
Views: 6404

Re: The MTX on Youtube

It's doing some strange things. The peripheral seems to be 16 bit in that it's loading values from ports 128 and 129 into HL, then it's comparing, looping until a value is the same as L.

I wonder what the heck it's doing.
by stephen_usher
11 Mar 2023 22:01
Forum: MFX
Topic: MFX mass-storage add-on - Storage Enhancement Request
Replies: 13
Views: 46684

Re: MFX mass-storage add-on - Storage Enhancement Request

Nice enhancement.

I notice GAL and CPLD updates too. Are they critical for early boards?