Sinclair ZX80 / ZX81 Forums

jdfan1000 wrote: ↑

Tue Jul 30, 2019 7:32 pm

Hi!

Do you know where this came from originally?

Thanks!

jd,

Designed by David Leech from Leesville, SC
He says the 8251 USART is good for 9600 bps.
b

Hi,
This is the backbone of the Byte Back Modem, activated by logic gates to test individual bits of an entire byte.
b
* docs attached *

This is a problem with ZXPand not the program. When generating standard ZX81 type characters SHREB expects to find the character patterns at $1E00, which are are no longer there because of the ZXPand overlay ROM. Pseudo-hi-res programs also have a similar problem. Try loading the program with the /...

Here it is with SHREB version 3. I haven't actually tried to figure out how the use the program, but the screen shot shows that SHREB version 3 is working. Regards; Greg Greg, The SHREB version 3 appears to handle Tom's SE graphics, but not regular text. If you know the subtlety between 2 and 3, pl...

mrtinb wrote: ↑

Mon Jul 08, 2019 5:05 am

https://github.com/charlierobson/ZXpand ... ine-Manual

mrtinb,
ZXpand did the job, thx!
Now, the attached >16K file ZXpand SAVEd, will not LOAD via EO tape, only ZXpand CAT.
What's the trick to get EO tape/wav to LOAD it, as well
b
* how many P standards exist *

If you have a ZXpand, you can load the software with LOAD “SOFTWARE STOP ”, where STOP is a keyword. ZXpand emulation is available on EightyOne as well. If you have real hardware with tape loading, I’ve read you can load with RAND USR 836 to stop auto-run. (This I’ve never tried myself.) mrtinb, Th...

Hi,
ZX software that auto-runs, after loading, has more of a chance to fail.
Q: Can auto-run code be unlocked in some way, so only the binary gets installed without it being launched
b

Merge 32kb version (only 20kb Basic memory available): Ram_Top @ 49999 TODO: Move the Ram_Top : POKE 16388,200 POKE 16389,175 NEW LOAD "MERGE32" LOAD the Program#1. RAND USR 45030 LOAD the Program#2 RAND USR 45000 Type LIST. [Tested on EO] Merge32.TZX MERGE32.P XavSnap, What I've noticed, one EO ve...

dessony wrote: ↑

Wed Jul 03, 2019 7:13 am

Does this device use an 8255 IC?

DesSony

dessony,
Yes, and here is the schematic to see how the hardware is wired . . .
b

Here it is with SHREB version 3. I haven't actually tried to figure out how the use the program, but the screen shot shows that SHREB version 3 is working. Regards; Greg Greg, It appears that the P file format is very unstable when the file exceeds 16K. Here is an example where EO can generate only...