I may have found a way to run H4th with the ZXpand.

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Moggy
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I may have found a way to run H4th with the ZXpand.

Post by Moggy » Tue Aug 08, 2017 8:14 pm

Tonight whilst fiddling about(OOER) I stumbled upon something that may be of interest to users of H4th.
As you know Tape load/save and RAM pack only is the drawback of a standard zeddy where h4th is concerned, but after a few key presses in sequence and a swift Xpand reset instead of the usual garbage you get when running a forth EPROM with the 'spand I not only managed to get the copyright message but ran a few simple programs as well, and when the Hforth command "MEM ." was entered instead of the usual 14k remaining It showed 31k!!

Not tried load or save yet but as the overlay is switched out it will still be tape unfortunately.

if any one wants to try it for themselves and have a suitably EPROM'D zeddy then try the following..........

1) power up the zeddy (holding shift if you have Xpand commander, to stop it running)

2) Ignore any garbage on screen and enter CONFIG X to switch out the overlay EPROM.
you wont see CONFIG X just garbage, just ignore and do it by feel.

3) Reset the 'spand with a quick tap (taking care not to wobble it) not the prolonged reset and at the top of the display should be a flashing black cursor.

4) Press SHIFT and SPACE together to perform H4th reset and the usual copyright message for Hfth should be displayed.


I would be interested to know if it works for anyone else.

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Andy Rea
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Re: I may have found a way to run H4th with the ZXpand.

Post by Andy Rea » Tue Aug 08, 2017 8:47 pm

Well the Moggy strikes again.... i really ought to get into forth i feel i'm missing the action somehow... anyway the ZXpand.... even thought the overlay rom is switched out it may still be possible, with the help of Sirmorris of course.... keep reading...

i was adding joystick support to my latest creation but since there is a chance that the program may get used on system without ZXpand then caling the API to read the joystick would be a no no... so i used a little routin by the great man himself to detect if spand was attached so far so good... joystick works as expected... now disable overlay and run again,,, CRASH... wuttttt...t.t.t.t.

a little debugging later, even though the overlay rom is disabled the Spand still responds if you send the right stuff down the IO...

so what do i think.... if this 'ere forth can read and write IO ports there is a slim chance that a "new word(s)" ( is that the right term? ) could be compiled that allow some sort of sd access ?

sits back and waits for SirMorris to FacePalm :lol:

Regards Andy

p.s. @Sirmorris if this 'ere spand still listens with the overlay off... is it possible to turn the overlay back on, without a reset ?
6 x ZX81, 1 x TS1500 , 1 x +3e, 1 x timex 2040 printer, 1 x timex 2020 cassette deck, siclair printer and some spectrum

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sirmorris
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Re: I may have found a way to run H4th with the ZXpand.

Post by sirmorris » Tue Aug 08, 2017 9:13 pm

No facepalming here.

Code: Select all

; disable overlay
  ld   bc,$e007
  ld   a,$b0
  out  (c),a

; re-enable overlay
  ld   bc,$e007
  ld   a,$b1
  out  (c),a
I dunno how easy it'd be but it's perfectly feasible to mod the FORTH rom or write machine code or even forth, as Andy so rightly points out, to load from SD.
--=== ZXpand+ ... A more moderner all-in-one upgrade solution for ZX81 ===--
* SD/MMC storage * 32K Hires-capable RAM * AY sound chip * Joystick port * Serial *
* BASIC enhancements - plug & play * Reset button * Auto-boot facility *

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Andy Rea
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Location: notts UK

Re: I may have found a way to run H4th with the ZXpand.

Post by Andy Rea » Tue Aug 08, 2017 9:31 pm

sirmorris wrote:
Tue Aug 08, 2017 9:13 pm
No facepalming here.

Code: Select all

; disable overlay
  ld   bc,$e007
  ld   a,$b0
  out  (c),a

; re-enable overlay
  ld   bc,$e007
  ld   a,$b1
  out  (c),a
I dunno how easy it'd be but it's perfectly feasible to mod the FORTH rom or write machine code or even forth, as Andy so rightly points out, to load from SD.
mucho gracias, Tokens de cerveza añadidos a su cuenta.

Sorry @ Moggy for slight thread hijack....

forth it is then...

Andy
6 x ZX81, 1 x TS1500 , 1 x +3e, 1 x timex 2040 printer, 1 x timex 2020 cassette deck, siclair printer and some spectrum

Moggy
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Re: I may have found a way to run H4th with the ZXpand.

Post by Moggy » Tue Aug 08, 2017 10:16 pm

Carry on guys the more the merrier :lol:


A couple of points to ponder...

1) The H4th EPROM uses it own semi-UDG character set( at this point Andy guesses what I was up to) plus store/load routines so needs to be switched in, in some manner unless the overlay EPROM can duplicate this?

2) The 'spand I used is an issue three with AY for reference, I tried an issue one NO JOY WHATSOEVER!! so later 'spands only perhaps?

3) It works without SD card so becoming a 32k RAM pack in essence, normal tape store/load works OK runs programs OK.

Hells teeth lads if you can find a way to get SD functionality by a bit of code tweaking I'll get the old spectrum burner and pack of 2764's out. :lol:

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sirmorris
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Re: I may have found a way to run H4th with the ZXpand.

Post by sirmorris » Tue Aug 08, 2017 10:27 pm

Moggy wrote:
Tue Aug 08, 2017 10:16 pm
2) The 'spand I used is an issue three with AY for reference, I tried an issue one NO JOY WHATSOEVER!! so later 'spands only perhaps?
:shock:

There should be no difference... Verrry interesting. What about an issue 5 ;)
--=== ZXpand+ ... A more moderner all-in-one upgrade solution for ZX81 ===--
* SD/MMC storage * 32K Hires-capable RAM * AY sound chip * Joystick port * Serial *
* BASIC enhancements - plug & play * Reset button * Auto-boot facility *

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sirmorris
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Location: oxon, uk

Re: I may have found a way to run H4th with the ZXpand.

Post by sirmorris » Tue Aug 08, 2017 10:30 pm

So does forth have any I/O commands? If not can you add machine code?
--=== ZXpand+ ... A more moderner all-in-one upgrade solution for ZX81 ===--
* SD/MMC storage * 32K Hires-capable RAM * AY sound chip * Joystick port * Serial *
* BASIC enhancements - plug & play * Reset button * Auto-boot facility *

Moggy
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Joined: Wed Jun 18, 2008 1:00 pm

Re: I may have found a way to run H4th with the ZXpand.

Post by Moggy » Tue Aug 08, 2017 10:34 pm

sirmorris wrote:
Tue Aug 08, 2017 10:27 pm
Moggy wrote:
Tue Aug 08, 2017 10:16 pm
2) The 'spand I used is an issue three with AY for reference, I tried an issue one NO JOY WHATSOEVER!! so later 'spands only perhaps?
:shock:

There should be no difference... Verrry interesting. What about an issue 5 ;)
Not tried a five that's on music duty at the mo-mo.

Just looking at my forth manual for I/O can't see anything other than store and load but it does have a built in assembler and I seem to remember that Skywave were going to issue a FP EPROM to accompany the H4th one and there is a space in the memory map for such a thing according to the manual at section 20.0.

@Charlie

Just remembered that the issue one is one that was knackered by yours truely and you managed to cobble it back together so may not be running pukker firmware possibly version "Just get Moggy going" 2.00
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Andy Rea
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Re: I may have found a way to run H4th with the ZXpand.

Post by Andy Rea » Tue Aug 08, 2017 10:45 pm

assembler is good...

how many Spands do you have Moggy ?

I'm really not much help here :mrgreen:
6 x ZX81, 1 x TS1500 , 1 x +3e, 1 x timex 2040 printer, 1 x timex 2020 cassette deck, siclair printer and some spectrum

Moggy
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Joined: Wed Jun 18, 2008 1:00 pm

Re: I may have found a way to run H4th with the ZXpand.

Post by Moggy » Tue Aug 08, 2017 10:53 pm

Andy Rea wrote:
Tue Aug 08, 2017 10:45 pm
assembler is good...

how many Spands do you have Moggy ?

I'm really not much help here :mrgreen:
Five.

Two for music, two for large number maths/encipherment which is an interest of mine and one for my ZX80.

Of the two music 'spands one is for MIDI, the other I use with Trick firmware (courtesy of the boss) with a stereo modified Zonx unit alongside the spands own AY for Turbosound as I find a four speaker dual amp setup a lot clearer and less muddy/distorted than Turbosound funnelled into normal stereo plus you can get a better balance that way.

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