FIF. Another FORTH.

Discussion about ZX80 / ZX81 Software
roganjosh
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Re: FIF. Another FORTH.

Post by roganjosh »

You're most welcome Moggy. I hope you're striking a decent balance between normal FORTH and artificially induced mind-expanded FORTH.
mrtinb wrote: Thu May 20, 2021 7:15 am Why is it required to use ZXpand in M=H mode? If you want to run the UDG version, you need memory at location 8k. To have memory at location 8k on the ZXpand, M=L mode is required.
The short answer to that is that I'm assuming for the moment that a Chroma 81 is placed between the ZX81 and the ZXpand and that switch 3 is set. That should work for UDGs and also give the maximum free RAM (I'm on the waiting list for a Chroma 81 but the documentation for it is clear and EO can be configured to provide a similar setup).

I've been assuming that UDG4ZXPAND boards would require an M=L version (to get RAM at $2000). However I cannot be sure. AFAIK, no new UDG4ZXPANDs are likely to be made (I've put myself on the SMR waiting list), no one wants to sell one and a PM to Andy Rea went unanswered and was subsequently either manually or automatically deleted. As I couldn't find any detailed documentation for UDG4ZXpand and, unlike Chroma 81, I couldn't directly contact the maker I left that configuration in limbo. If someone can point me to some definitive documentation that describes how UDG4ZXPAND (safely) interacts with ZXpand and/or Chroma 81 in all possible configurations then suitable M=L version/s could be produced for it.

That's not to say that at some stage a M=L version won't appear for the Chroma 81 - I'm still thinking about configurations to support colour (or, more accurately, have been taking a short break and will return to that soon). Anyway, at least the documentation currently does state that M=H is required and that, for UDG, there must be RAM at $2000 (which is possibly enough to suggest that Chroma 81 will work and UDG4ZXPAND won't).

Alan
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mrtinb
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Re: FIF. Another FORTH.

Post by mrtinb »

I ask, because I have both ZXpand+ and UDG4ZXpand. But I don't have Chroma 81.

Great work by the way.
Martin
https://zx.rtin.be
ZX81, Lambda 8300, Commodore 64, Mac G4 Cube
roganjosh
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Re: FIF. Another FORTH.

Post by roganjosh »

Version 0.11 is now available at the top of the thread. It increases the Line Buffer size to 254 bytes.

Thanks for the kind words Moggy & Martin. They warm the cockles (Matron!).


Alan
Moggy
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Re: FIF. Another FORTH.

Post by Moggy »

254 bytes most excellent. :D

Like Martin I too have the ZXpandudg jobby but for some strange reason never considered using it, so tonight's the night Josephine.

As for how to use it some technical babble posted here might help you Alan.

viewtopic.php?t=2533

As for Andy I think like Sir Morris he has gone for good from the forum and apart from the odd PM in 2019 I haven't personally spoken to him since we met up at the retro computer museum a few years ago.

I will PM him and see if I have any luck.

Just a thought is there any way to check how much memory left IE MEM . as per H4th?
Last edited by Moggy on Thu May 20, 2021 5:05 pm, edited 1 time in total.
roganjosh
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Re: FIF. Another FORTH.

Post by roganjosh »

It's pointless trying the P files at the top of the thread with a UDG4ZXPAND as they won't work. The following version might. It needs to be configured with "M=L" . Also remember to put the CHARSET.BIN file in the same directory as the P file.

fifudg4.p
(9.36 KiB) Downloaded 86 times

It's hastily cobbled together, untested and you'll currently lose 8K as I'd need to reorganise memory usage specifically for the UDG4ZXPAND to claim some of it back. Anyway, let me know whether it works (look for '@!#&' etc during a VLIST). The documentation shows how the new characters are mapped.

As for free memory - a reasonable approximation would be given by:

Code: Select all

HEX C000 DP @ - U.
but change the C000 to A000 if using the UDG4ZXPAND P file above. I can add a more accurate word in the next release if it's helpful. On it's own:

Code: Select all

DP @ U.
is useful to check whether you're still in the first 32K (e.g. for machine code or new defining words).

Thanks for the link etc. It'd be nice to know whether he'd mind being contacted for technical issues.

Alan
Last edited by roganjosh on Thu May 20, 2021 8:34 pm, edited 1 time in total.
Moggy
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Re: FIF. Another FORTH.

Post by Moggy »

Alas no joy with this I'm afraid.

It appears to load but gives error report ZXPAND ERROR 4.
VLIST does show the vocabulary with just basic characters for the UDG bits and the program won't actually run.

For example.

2 2 + . just gives a question mark as does any other command.
roganjosh
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Re: FIF. Another FORTH.

Post by roganjosh »

Moggy wrote: Thu May 20, 2021 7:32 pm Alas no joy with this I'm afraid.

It appears to load but gives error report ZXPAND ERROR 4.
One thing at a time. the above error usually means that you haven't copied the CHARSET.BIN file to the same directory as the P file you're trying to run. Can you verify that first?

Alan
Moggy
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Re: FIF. Another FORTH.

Post by Moggy »

Yup copied across.
roganjosh
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Re: FIF. Another FORTH.

Post by roganjosh »

Are you starting it using a standard LOAD command or from some sort of UI?

Alan
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Re: FIF. Another FORTH.

Post by Moggy »

Yes standard navigate and LOAD.

Discovered the problem (I think)

When you navigate to the FIF81 directory in the usual manner and load FIF81 the command DIR lists the contents of said directory however when FIFUDG4 is loaded it then immediately defaults to the root directory which a quick DIR confirms and as such cannot find the binary file.

I copied the binary to root and it appears to now be working insofar as the UDGS show in VLIST so now will check the rest is working.
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