Search found 52 matches

by fordp2002
Fri Jan 08, 2021 4:55 pm
Forum: Development
Topic: ZX21 Project ZX81 Replacement PCB
Replies: 61
Views: 22092

Re: ZX21 Project ZX81 Replacement PCB

I didn't notice the DB9 connector until I looked at the recent picture. Is that a standard RS232 port? Yes like Mark says it is a Joystick port. A serial port on a ZX81 is much rarer than a joystick port and hence has less software out there that can use one. There is some mention of using WESPI to...
by fordp2002
Fri Jan 08, 2021 4:51 pm
Forum: Development
Topic: ZX21 Project ZX81 Replacement PCB
Replies: 61
Views: 22092

Re: ZX21 Project ZX81 Replacement PCB

OK, I have been working on getting the YMZ284 sound going today. Well after quite a bit of RTFM I found a few issues with my design. I only roughed it out on this first version as I was pretty sure it was not going to work as this was a new design. Well, the first hint is that for IO decoding there ...
by fordp2002
Tue Jan 05, 2021 10:23 pm
Forum: Development
Topic: ZX21 Project ZX81 Replacement PCB
Replies: 61
Views: 22092

Re: ZX21 Project ZX81 Replacement PCB

Easier on the ZX21 as pretty much all the signals are on one of three debug connectors.
by fordp2002
Sun Jan 03, 2021 3:33 pm
Forum: Development
Topic: ZX21 Project ZX81 Replacement PCB
Replies: 61
Views: 22092

Re: ZX21 Project ZX81 Replacement PCB

Suggestion: - Add the internal 32k ram with the Wrx patch . - Add an address rom mirroring for the offset $0004=$7F to $FF (by switch ?) 32k >> if address data=$0004 + \romcs + \Mreq = DATA>$FF Zx ROM to init the memory room: (set the ram_top to $FFFF) 0000 D3;FD OUT ($FD),A ; ZX81 NMI GENERATOR 00...
by fordp2002
Fri Jan 01, 2021 2:34 am
Forum: Development
Topic: ZX21 Project ZX81 Replacement PCB
Replies: 61
Views: 22092

Re: ZX21 Project ZX81 Replacement PCB

Happy new year all. 2021 the year of the ZX21 project!
by fordp2002
Wed Dec 30, 2020 10:13 pm
Forum: Development
Topic: ZX21 Project ZX81 Replacement PCB
Replies: 61
Views: 22092

Re: ZX21 Project ZX81 Replacement PCB

Hi, Is a Bluetooth module can be used instead of the ESP32 on ZX-Wespi project ? For input or output transferts: Bluetooth-Audio-Transmitter-Module-Board-4-1-Stereo-Audio-GFSK-Transceiver-Wireless-Speaker-Headphones-KCX-BT Bluetooth-Audio-Transmitter-Module-Board-4-1-Stereo-Audio-GFSK-Transceiver-W...
by fordp2002
Tue Dec 29, 2020 7:48 pm
Forum: Hardware
Topic: Faulty dk'tronics KEYBOARD
Replies: 8
Views: 2139

Re: Faulty dk'tronics KEYBOARD

Thanks for the replies. The switch on top was the P key and I did try contact cleaner and much bashing. I did take it apart but the bit of metal inside was not in a good way and I gave up trying to make it work again.
by fordp2002
Tue Dec 29, 2020 4:20 pm
Forum: Hardware
Topic: Faulty dk'tronics KEYBOARD
Replies: 8
Views: 2139

Faulty dk'tronics KEYBOARD

IMG_20201229_151619.jpg
I have some faulty keys on my keyboard does anyone know of a source of spare key switches?

Also I could not see any other keyboards just like this on the web (repeat key and no numeric keypad) does anyone have information about this model. (I was given it by a friend).
by fordp2002
Mon Dec 28, 2020 5:41 pm
Forum: Development
Topic: ZX21 Project ZX81 Replacement PCB
Replies: 61
Views: 22092

Re: ZX21 Project ZX81 Replacement PCB

IMG_20201228_161417.jpg
I am starting to look at getting the sound working. I have a "organ" program typed in from the zonx81 manual.
by fordp2002
Mon Dec 28, 2020 4:45 pm
Forum: Hardware
Topic: Internal AY-8912, has anyone tried it?
Replies: 16
Views: 3671

Re: Internal AY-8912, has anyone tried it?

I am working on getting the ZX21 sound working. I am using the YMZ-284 chip board option and I have typed some of the programs in from the ZONX81 Manual (Ian Priddey).

I will as at the very least add the .p files to my github.