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Original JS ROM Set
Posted: Thu Jul 11, 2024 1:57 pm
by t0nyt
I was wondering if anyone has an original JS ROM set they'd be willing to sell please?
(For my use on this QL I don't think I'll have the head room for one of Chr$ ROM Boards)
Many thanks
Tony
Re: Original JS ROM Set
Posted: Thu Jul 11, 2024 5:01 pm
by Derek_Stewart
Hi Tony
I should have some JS ROMS, I will check and get back to you.
Re: Original JS ROM Set
Posted: Thu Jul 11, 2024 5:41 pm
by t0nyt
Derek_Stewart wrote: Thu Jul 11, 2024 5:01 pm
Hi Tony
I should have some JS ROMS, I will check and get back to you.
Many thanks Derek
Re: Original JS ROM Set
Posted: Sat Jul 13, 2024 10:30 am
by t0nyt
I know, from a previous thread, that I can't use 2 x 32KB EPROM in the QL (without modifications to the mobo)
But reading a few threads on here there seems to be some suggestion that 1 x 64KB EPROM could be used (without modifications?)
Is this just a wishful interpretation or actually correct please?
Just looking for a temporary solution until I have some real JS ROM's
Many thanks
Re: Original JS ROM Set
Posted: Sat Jul 13, 2024 10:43 am
by t0nyt
t0nyt wrote: Sat Jul 13, 2024 10:30 am
I know, from a previous thread, that I can't use 2 x 32KB EPROM in the QL (without modifications to the mobo)
But reading a few threads on here there seems to be some suggestion that 1 x 64KB EPROM could be used (without modifications?)
Is this just a wishful interpretation or actually correct please?
Just looking for a temporary solution until I have some real JS ROM's
Many thanks
Thinking about it I guess even if that did work it would tie up the 16k at $c000 knocking out things like QIMSI
Re: Original JS ROM Set
Posted: Sat Jul 13, 2024 11:13 am
by Martin_Head
If a MK1 Minerva would fit in your QL. You could burn the JS code onto a 64K EPROM and replace the Minerva ROM wit it.
Re: Original JS ROM Set
Posted: Sat Jul 13, 2024 11:21 am
by t0nyt
Martin_Head wrote: Sat Jul 13, 2024 11:13 am
If a MK1 Minerva would fit in your QL. You could burn the JS code onto a 64K EPROM and replace the Minerva ROM wit it.
Hi Martin
I took the plunge with one of Chr$ daughter boards I had spare this morning and it turns out it will JUST fit in this QL (but it's Minerva 1.98 A1, and I'd prefer JS ROM) so have PM'd Chr$ to see if he can supply me a JS one to save troubling Derek
Would the 64K EPROM not prevent QIMSI and other ROM Port plug-ins working at $C000 though?
Many thanks
Re: Original JS ROM Set
Posted: Sat Jul 13, 2024 11:58 am
by t0nyt
Just to be clear, my concern about Chr$ board fitting was related to the QL, not the boards
They are excellent and I use them in all my other QL’s!
Re: Original JS ROM Set
Posted: Sun Jul 14, 2024 4:08 pm
by Martin_Head
t0nyt wrote: Sat Jul 13, 2024 11:21 am
Martin_Head wrote: Sat Jul 13, 2024 11:13 am
If a MK1 Minerva would fit in your QL. You could burn the JS code onto a 64K EPROM and replace the Minerva ROM wit it.
Hi Martin
I took the plunge with one of Chr$ daughter boards I had spare this morning and it turns out it will JUST fit in this QL (but it's Minerva 1.98 A1, and I'd prefer JS ROM) so have PM'd Chr$ to see if he can supply me a JS one to save troubling Derek
Would the 64K EPROM not prevent QIMSI and other ROM Port plug-ins working at $C000 though?
Many thanks
The MK1 Minerva had a logic IC under the EPROM that switched the EPROM out at $C000 to leave the ROM port free. If you look at a Minerva ROM it should be a 64K one. I don't know about the EPROM that Chr$ uses.
Re: Original JS ROM Set
Posted: Sun Jul 14, 2024 4:12 pm
by Chr$
t0nyt wrote: Sat Jul 13, 2024 11:21 am
Would the 64K EPROM not prevent QIMSI and other ROM Port plug-ins working at $C000 though?
Many thanks
It will if the TK2 part of the 64k EPROM is enabled with the jumper.... with it disabled the 16k starting at $C000 is free to be used by whatever is using the normal ROM port 16k chunk.