Sinclair ZX80 / ZX81 / Z88 Forums

Maybe Greg has a HAL 81?

https://en.wikipedia.org/wiki/HAL_9000

WIKI wrote: Origin of name
HAL's name, according to writer Arthur C. Clarke, is derived from Heuristically programmed ALgorithmic computer.[7] After the film was released fans noticed HAL was a one-letter shift from the name IBM

Siggi

When I saw HAL I thought Hardware Abstraction Layer. Windows uses this to isolate the OS from actual hardware. This way Windows only deals with a generic interface to say, video, and the hardware manufacturer has to develop a driver to deal with the specifics of the hardware. But I highly doubt that is what is meant since the ZX81 would not have the memory for it. HAL is one reason I love the old 8 bit computers. There isn't that headache when interfacing hardware to them.

I too named my first ever computer, my ZX81 kit, HAL. It just seemed right.

I may have an issue with loading to Flash. I can load a program such as Mazogs.p with no problem but when I try loading ZX-Assembler 2 into flash using
ZXA2-8KC.C:$2000:1*
The screen goes blank (like in fast mode) indefinitely. I've waited over 2 minutes with no change. I finally reset the ZX81 then do a Debug of the addresses at $2000 instance 1 and see mainly $00 with some random values but nothing that would be enough to be a working program. I also changed the file to ZXA2-8KC.BIN with no change.

I will check that.

More problems with the clock. Last week I was able to change the time by removing and reinstalling the battery. Last Sunday was "daylight savings" in the USA which means add one hour to the clock. When I tried to add the hour it won't update again! I shouldn't have to remove the battery to update the clock.

The problem described by blittle is the same as I'm having, as noted in the PM I sent you. I tried installing the H4TH.rom and SG81.rom both crashed. I tried installing memocalc.rom at $3000 also crashed. I tried again to install a RAM version of it, it didn't crash but it also didn't load the data correctly.

Regards;

Greg

GCHarder wrote: ↑Thu Mar 16, 2017 12:11 am When I tried to add the hour it won't update again! I shouldn't have to remove the battery to update the clock.

What keys do you use to move to the time ?
Only NEWLINE is allowed or entering full valid date/time with the keyboard.
I adjusted my clock several times with no problems at all and did not hear about a problem from other side here.

This is the first release of ZXblast and there may be a few bugs in the firmware which can be surely corrected in future versions. The first release is maybe more suitable for mainstream users.

H4TH rom will not run with ZXblast now. Remember - this is not an emulator where you can really exchange a rom inside of the ZX81. In the manual of Husband Forth it is explicitly stated, that you have to change the internal rom - if not socketed with a side cutter (!). This is technical stuff and has to do with the internal character generator logic - this has been discussed in another thread shortly. About SG81 - not tested myself yet.

By the way - H4TH has some more restrictions and a very strange memory handling. It requires mirroring of RAM and ROM and usually runs with 16k memory only. I think EightyOne was hacked to get H4TH run anyway - did write about it somewhere else a few month ago regarding test with ZXmore and H4TH. I now some guy working on a modified H4TH version to get it run with both - ZXmore and ZXblast. But this is a recompiled version with original ZX81 charset at the right place ($1E00-$1FFF).

By the way - there is a bug in setting date and a wrong implemented plausibility check. Day is checked to be max. $31 (bcd value accepted from RTC only) but compared or set maximum to numeric 31. Same is for month, checked for 12 instead of $12. So setting the clock may give bad results if done with day >= 20 and month >=10. Not sure if this will give some malfunction inside the RTC chip when date is moved internally from $1F (=31) upwards. This is solved in the next release which should be available end of this month.

So better avoid setting the correct time with daylight saving until the new release is available. Removing the battery of RTC is a workaround only. Whenever the date with 1F.02.2017 was entered I was able to correct it soon. But never let the clock run further with the wrong date, so not sure what will happen.

Thanks for looking into this Karl. I am a software programmer and many things I have written looks and acts great but not long after it gets released we may get calls that the change doesn't work right or affected something else. I don't mind if I'm a tester . Let me know if I find anything else if you want me to send a PM or post it on this thread.

I was thinking that one of the differences between static ram and flash is the write time in flash is slower. Could timing for writes be too fast causing the issue in loading Flash?