Sinclair ZX80 / ZX81 Forums

[Moggy]

BTW in the late 80's I designed a MIDI interface for the ZX-81. I wrote it up in an article in the TSUG newsletter (Toronto Sinclair Users Group) 2 issues I believe. There were some problems using it in slow mode as I recall mainly due to I/O port addressing (even/odd is no good). But I wrote some software that would do MIDI thru and playback a short MIDI file that worked OK. I think it only played back 1 channel and there could not be too many notes. My goal was originally to make a 8/16 step sequencer and build it into a keyboard I was putting together. That was never completed. With the SD card the storage issue is resoved nicely.
I will try to dig this up if there is interest. I think with the SD card for storage and an 8/16 step sequencer as a goal, perhaps synched to the timecode from a drum machine this could be a viable toy. The stuff from that endeavour is probably kicking around in the garage.


Pterodactyl

YESSSS!! MIDI I knew someone had done it, Please ressurect said device! As a muso who has used MIDI from day one I would really love to see this one fly. It was done on the speccy with the RAM Music machine so why not the zeddy? Like You say with SD storage this looks good. Memory boards are fun too I have a couple of Hunter boards which have been very useful. This thread is getting better all the time. a hearty Welcome to the forum pterodactyl.

Regards Moggy

[Mike3]

Hey sirmorris....

Still looking forward to the SD interface... How goes it?

Regards... Mike

[pterodactyl]

Well.. last weekend I had a root through the stuff in the garage and... I found a big box of ZX-81 stuff. Lots of food for my imagination here! I located the MIDI interface and connected my souped up ZX-81 (built on a slab of aluminum plate as it long ago outgrew the case) but my monitor is toast . I want to try to make a VGA adapter to connect to one of the Viewsonics LCD monitors I have in the lab - has anyone done this?

I have so far found:
memory packs of various designs and sizes some I built some are bought like Memotech and Gladstone
a gamma ray spectroscope that interfaces to a TS-1500, the TS-1500 has a Larken disk interface that uses 720K 3.5" floppies and this unit has RGB out and a centronics printer i/f
1 ZX-81 still in original box with a printer and 16K memory pack
6 cased ZX-81s some modded
8 uncased ZX-81 boards
an external keyboard
25 various Gladstone Basicare ZX-81 add-on modules - anyone have info on these?
tons of stuff and PCBs I designed years ago
2 ZX-Printers and a box of parts
3 Larken ZX-81 floppy disk interfaces - I wonder can these be used with 720K or 1.4 MB drives? Maybe with some mods?
external ZX-81 keyboard that has a built in macro recorder feature - don't know if it still works but I know it did
MIDI interface and technical docs and all my TS/ZX books and papers
There is more - I'm sure.

[gus]

Well.. last weekend I had a root through the stuff in the garage and... I found a big box of ZX-81 stuff. Lots of food for my imagination here! I located the MIDI interface and connected my souped up ZX-81 (built on a slab of aluminum plate as it long ago outgrew the case) but my monitor is toast . I want to try to make a VGA adapter to connect to one of the Viewsonics LCD monitors I have in the lab - has anyone done this?

I have so far found:
memory packs of various designs and sizes some I built some are bought like Memotech and Gladstone
a gamma ray spectroscope that interfaces to a TS-1500, the TS-1500 has a Larken disk interface that uses 720K 3.5" floppies and this unit has RGB out and a centronics printer i/f
1 ZX-81 still in original box with a printer and 16K memory pack
6 cased ZX-81s some modded
8 uncased ZX-81 boards
an external keyboard
25 various Gladstone Basicare ZX-81 add-on modules - anyone have info on these?
tons of stuff and PCBs I designed years ago
2 ZX-Printers and a box of parts
3 Larken ZX-81 floppy disk interfaces - I wonder can these be used with 720K or 1.4 MB drives? Maybe with some mods?
external ZX-81 keyboard that has a built in macro recorder feature - don't know if it still works but I know it did
MIDI interface and technical docs and all my TS/ZX books and papers
There is more - I'm sure.

You are telling us that you have more that one larken interface ? can you please post some pictures ???
Thanks and enjoy it !
Gus

[pterodactyl]

I wanted to post a pdf of the MIDI interface but this board won't accept the file? Is it set to just accept jpg?

[RWAP]

Yes it only accepts jpgs - the problem with pdfs is the amount of storage space required. Email it to me via my website www.rwapsoftware.co.uk and I will upload it onto one of my servers and add a link

[sirmorris]

SD Interface is 2 steps closer. I have successfully written to and read from the PIC. Tomorrow I'll have the PIC firmware modified so that it understands ZX character codes. From then it'll be only a very minor step away from reading programs and directory listings from the card.

C

[pterodactyl]

With regards to the the ZX-81 MIDI interface article: I tried to send a mail via the web site you provided, however I get a 'service not found' or an 'error page not found' when I click on the contact link. Maybe I'm doing something wrong or there is a server issue at one end or the other.
Please email me you email address to: Lou at pterodactylrecords dot com. if you like and I will reply with the file.

[Mike3]

Great Sirmorris....

glad to here the progress... and Appreciate your efforts....

Regards... Mike

[handsgofirst]

Hello all: Newbie to this Forum, just found you and delighted to be here. So many knowledgeable folks still flogging the ZX-81. It makes my old heart flutter. The ZX-81 was not my first, back in the day, just the best. I also played with a ZX-80 development kit and went way deeper into the SWTP dinosaur than common sense and pocket money should have allowed. My business took me into the IBM-PC world thanks to AutoCad86 and I was spoiled.

Making a long story short, I have dusted off my ZX-81 gear and if I could only find a manual for my Computer Continuum Buffered Expansion board and analog board I could be happy. I would be even happier to see this SD/MMC expansion project result in hardware in my hand. Please put me down for one definitely and perhaps a second too. I also am interested in the MIDI device. And an LCD composite monitor in ~9" size. The adapter for a standard
PC keyboard is interesting because there are some compact sizes still available but I do like the outboard chiclet ZX-81 keyboard I added in those early years (can't remember the brand offhand). Just bought a new 2040 printer and am hoping I can sub some (fax?) paper somehow; need to do some more research on that.

Sirmorris: Bless you. What is the latest on the SD/MMC please? I am beyond ready to send an order.