Search found 204 matches

by blittled
Wed Mar 10, 2021 6:10 pm
Forum: GAMES
Topic: Phoenix ZX81 arcade conversion
Replies: 20
Views: 2344

Re: Phoenix ZX81 arcade conversion

I believe marste has a Kickstarter page for Real Chess viewtopic.php?f=4&t=4080&p=41658#p41658
by blittled
Mon Mar 08, 2021 9:36 pm
Forum: Hardware
Topic: Another PCB, again ;)
Replies: 6
Views: 717

Re: Another PCB, again ;)

Awesome! Just what I'd need for a new home for my spare ZX81 ROM Chip and one of my Z80 chips :)
by blittled
Thu Mar 04, 2021 3:26 pm
Forum: Hardware
Topic: 3.3V logic with the ULA
Replies: 1
Views: 306

3.3V logic with the ULA

I am planning on doing some experimenting with the Teensy 3.5 controlling the memory using BusRQ, BusACK and the control lines that may falsely trigger the ULA. The Teensy is 5 volt tolerant so inputs are not a concern but the output is 3.3V logic. Most 5V logic chips will trigger a high with a high...
by blittled
Fri Jan 08, 2021 1:58 pm
Forum: Development
Topic: ZX21 Project ZX81 Replacement PCB
Replies: 61
Views: 6228

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?
by blittled
Fri Dec 18, 2020 7:33 pm
Forum: Development
Topic: ZX21 Project ZX81 Replacement PCB
Replies: 61
Views: 6228

Re: ZX21 Project ZX81 Replacement PCB

Can't wait to see how it works! :D . I'm going to start looking into replacement ULAs. I don't want to cannibalize the ZX81s I have to build another one. I know this will be opensource so it'll be up to me to find a pcb fab house and send the gerbers to them.... unless someone makes a run of pcbs an...
by blittled
Tue Dec 08, 2020 4:24 am
Forum: Development
Topic: New prototype ZX-deluxe+
Replies: 19
Views: 2100

Re: New prototype ZX-deluxe+

The price is a little to steep for me so I'm not interested. It is the best clone I've ever seen but I can't justify buying it. :(
by blittled
Thu Dec 03, 2020 2:04 pm
Forum: Development
Topic: New prototype ZX-deluxe+
Replies: 19
Views: 2100

Re: New prototype ZX-deluxe+

Very impressive! Time to start collecting all my loose change and break open the piggy bank to get one! Any idea when it'll be ready? If sometime midspring I may be able to put it on my birthday list :)
by blittled
Tue Oct 06, 2020 9:30 pm
Forum: Sinclair Misc
Topic: Where can I find "true" ZX81 fonts
Replies: 18
Views: 8875

Re: Where can I find "true" ZX81 fonts

mrtinb I actually was taught Fortran and 6502 assembly. The 6502 at the time looked like the cpu of the future (it didn't help that the university wasn't too far from where they developed the 6502) :D Things are getting a bit off target here. Once I get the zx81 emulation part working (hopefully by ...
by blittled
Tue Oct 06, 2020 6:28 pm
Forum: Sinclair Misc
Topic: Where can I find "true" ZX81 fonts
Replies: 18
Views: 8875

Re: Where can I find "true" ZX81 fonts

I'm glad to see I'm in good company :D
by blittled
Tue Oct 06, 2020 4:04 am
Forum: Sinclair Misc
Topic: Where can I find "true" ZX81 fonts
Replies: 18
Views: 8875

Re: Where can I find "true" ZX81 fonts

siggi, those are interesting links and may be something worth implementing once I get things going. Right now I'm having fun trying to implement the interrupts required to do the display. The Z80 engine I'm using counts t-states so I'm using that for the 207 count for the NMI. It isn't exact but sin...