ROM replacement services
9 messages · 2007-05-03 → 2007-05-09 · Yahoo Group era · View archive on archive.org
Participants: Jarek Adamski, Richard Atkinson, Jim Delaney, Mark Martin, Peter H Hoffman
Preserved from the Timex/Sinclair 2068 Yahoo Group (2001–2019), which is no longer online. Text reproduced from the archive.org archive; email addresses masked.
Messages
1. ROM replacement services
Richard Atkinson · Thu, 3 May 2007 11:03:
Hi all,
I am thinking of offering TS2068 ROM replacement services and thought
I'd send a quick e-mail here to see if there would be any interest.
Basically the idea is to provide TS2068s modified with Spectrum ROMs.
You'd send me a TS2068 and some cash, and I'd send back a machine
which thought it was a Spectrum. It would have the same (or better)
compatibility as a TS2068 with a Spectrum emulator cartridge, just
negating the need for a rare Spectrum emulator cartridge.
Optionally a switched ROM could be provided to select between the
TS2068 ROM set and the Spectrum ROM. This would be more expensive
because the parts and labour count would be higher.
I'm sure various people have offered services like this in the past,
but I would focus on the (tiny) UK market and any US customers
prepared to pay the cost of transatlantic shipping. I could include
free Spectrum cassette games as an additional bonus to my US customers
:)
Richard
2. Re: [ts2068] ROM replacement services
Mark Martin · Thu, 3 May 2007 09:15:
Richard,
Care to post some estimates for price on both the single and switched rom
replacements? I'm definitely interested.
I'm assuming the switched ROM would mean a toggle switch integrated into the
case?
Thanks,
Mark
On 5/3/07, Richard Atkinson <[email]> wrote:
>
> Hi all,
>
> I am thinking of offering TS2068 ROM replacement services and thought
> I'd send a quick e-mail here to see if there would be any interest.
>
> Basically the idea is to provide TS2068s modified with Spectrum ROMs.
> You'd send me a TS2068 and some cash, and I'd send back a machine
> which thought it was a Spectrum. It would have the same (or better)
> compatibility as a TS2068 with a Spectrum emulator cartridge, just
> negating the need for a rare Spectrum emulator cartridge.
>
> Optionally a switched ROM could be provided to select between the
> TS2068 ROM set and the Spectrum ROM. This would be more expensive
> because the parts and labour count would be higher.
>
> I'm sure various people have offered services like this in the past,
> but I would focus on the (tiny) UK market and any US customers
> prepared to pay the cost of transatlantic shipping. I could include
> free Spectrum cassette games as an additional bonus to my US customers
> :)
>
> Richard
>
>
--
------------------------------------------------------
Born to the false world, the wanderer,
Storyteller, The Pied Piper
On a quest for immortality
Gathering a troop to find the fantasy
-- Nightwish
3. Re: [ts2068] Re: ROM replacement services
Jim Delaney · Thu, 3 May 2007 17:55:
Jarek Adamski <[email]> wrote: Hello Richard!
--- In [email], "Richard Atkinson" <rga24@...> wrote:
> I am thinking of offering TS2068 ROM replacement services and
> thought I'd send a quick e-mail here to see if there would be
> any interest.
If you would be interested, I have some solutions for Timex 2068,
like OUT switchable ROM banks (FlashD0) and 512kB RAM upgrade.
Also cartridges.
I would be happy to send the boards, schematics and assembly
details and let you mount and distribute in UK.
Jarek Adamski
Hi Jarek, are you talking to me, Jim ? - I am allelectrix. If these circuits are
designed for a Z80 based system, I am interested in using them on a
ZX81 redesign .
I am therefore happy to asist you.
thanks, Jim, allelectrix
---------------------------------
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4. Re: ROM replacement services
Jarek Adamski · Thu, 03 May 2007 15:42
Hello Richard!
--- In [email], "Richard Atkinson" <rga24@...> wrote:
> I am thinking of offering TS2068 ROM replacement services and
> thought I'd send a quick e-mail here to see if there would be
> any interest.
If you would be interested, I have some solutions for Timex 2068,
like OUT switchable ROM banks (FlashD0) and 512kB RAM upgrade.
Also cartridges.
I would be happy to send the boards, schematics and assembly
details and let you mount and distribute in UK.
Jarek Adamski
5. Re: ROM replacement services
Jarek Adamski · Thu, 03 May 2007 22:07
Helllo Jim!
--- In [email], Jim Delaney <allelectrix2@...> wrote:
> Hi Jarek, are you talking to me, Jim ? - I am allelectrix.
Well, I was going to build a world-wide 8bit service
network... but I'm busy with other things, so this takes
time... Why not? :)
> If these circuits are designed for a Z80 based system, I
> am interested in using them on a ZX81 redesign .
The FlashD0 could be probably used in ZX81, I was thinking
about using the LD A,bank:OUT (#FC),A switching. The second
possibility is to use LD A,bank:IN A,(#FD), but the board
needs to be redesigned. The other problem is, that Timex
and Spectrum decodes the ROM using A14 and A15, while the
ZX81 probably also includes /RD, so decoding it for writing
may be a problem to solve. See:
http://www.ts1000.us/cgi-bin/yabb/YaBB.pl?board=IDEAS;action=display;num=1177073682
The 512kB SRAM is designed to be paged as 64kB banks (this
is no problem while 2068 architecture). But with little
modification can be used as 32kB (32k-64k) or even 16k
(48k-64k). We could put some thinking how this could be
used in ZX81 in the best way.
> I am therefore happy to asist you.
And I'm looking forward to cooperation. :)
Jarek Adamski
6. Re: [ts2068] Re: ROM replacement services
Jim Delaney · Fri, 4 May 2007 04:54:
Jarek Adamski <[email]> wrote: Helllo Jim!
--- In [email], Jim Delaney <allelectrix2@...> wrote:
> Hi Jarek, are you talking to me, Jim ? - I am allelectrix.
Well, I was going to build a world-wide 8bit service
network... but I'm busy with other things, so this takes
time... Why not? :)
> If these circuits are designed for a Z80 based system, I
> am interested in using them on a ZX81 redesign .
The FlashD0 could be probably used in ZX81, I was thinking
about using the LD A,bank:OUT (#FC),A switching. The second
possibility is to use LD A,bank:IN A,(#FD), but the board
needs to be redesigned. The other problem is, that Timex
and Spectrum decodes the ROM using A14 and A15, while the
ZX81 probably also includes /RD, so decoding it for writing
may be a problem to solve. See:
http://www.ts1000.us/cgi-bin/yabb/YaBB.pl?board=IDEAS;action=display;num=1177073682
The 512kB SRAM is designed to be paged as 64kB banks (this
is no problem while 2068 architecture). But with little
modification can be used as 32kB (32k-64k) or even 16k
(48k-64k). We could put some thinking how this could be
used in ZX81 in the best way.
> I am therefore happy to asist you.
And I'm looking forward to cooperation. :)
Jarek Ad
Thanks Jarek, that sounds great, I'm currently working on a big ZX81
project at the mo, so when I get a little more time, I can assist you with this.
thanks mate, Jim
---------------------------------
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7. Re: [ts2068] ROM replacement services
Richard Atkinson · Wed, 9 May 2007 11:02:
Hi Mark,
You're right, the switched ROM would mean a toggle switch installed into the
case, although it could be left on a flying lead if you didn't want a hole
drilled into your TS2068. I'm still ascertaining costs, but I'd estimate
that the switched ROM installation would take about twice the length of time
as the single ROM.
I've done some preliminary investigations, involving discussions with Jarek
(to whom I owe a great deal of thanks) and taking apart every single one of
my Timex Sinclair 2068s (six of them) and Timex Computer 2068s (two). It
seems the mod can be done more easily for the American TS2068 than for the
Portuguese TC2068.
There is a fair degree of choice available for different ROM modifications.
I will summarise these and suggest recommended options (giving reasoning) on
a web page for the service.
Richard
On 5/3/07, Mark Martin <[email]> wrote:
>
> Richard,
>
> Care to post some estimates for price on both the single and switched romreplacements? I'm definitely interested.
>
> I'm assuming the switched ROM would mean a toggle switch integrated into
> the case?
>
> Thanks,
> Mark
>
> On 5/3/07, Richard Atkinson <[email]> wrote:
> >
> > Hi all,
> >
> > I am thinking of offering TS2068 ROM replacement services and thought
> > I'd send a quick e-mail here to see if there would be any interest.
> >
> > Basically the idea is to provide TS2068s modified with Spectrum ROMs.
> > You'd send me a TS2068 and some cash, and I'd send back a machine
> > which thought it was a Spectrum. It would have the same (or better)
> > compatibility as a TS2068 with a Spectrum emulator cartridge, just
> > negating the need for a rare Spectrum emulator cartridge.
> >
> > Optionally a switched ROM could be provided to select between the
> > TS2068 ROM set and the Spectrum ROM. This would be more expensive
> > because the parts and labour count would be higher.
> >
> > I'm sure various people have offered services like this in the past,
> > but I would focus on the (tiny) UK market and any US customers
> > prepared to pay the cost of transatlantic shipping. I could include
> > free Spectrum cassette games as an additional bonus to my US customers
> > :)
> >
> > Richard
> >
>
>
>
> --
> ------------------------------------------------------
> Born to the false world, the wanderer,
> Storyteller, The Pied Piper
> On a quest for immortality
> Gathering a troop to find the fantasy
> -- Nightwish
>
8. RE: [ts2068] ROM replacement services
Peter H Hoffman · Wed, 9 May 2007 10:02:
As an idea for an aesthetically pleasing yet not damaging method of
switching between ROMs: at one time there was a kit which used an external
magnet and an internal reed switch to do the job.
-- Peter.
From: [email] [mailto:[email]] On Behalf Of
Richard Atkinson
Sent: Wednesday, May 09, 2007 6:03 AM
To: [email]
Subject: Re: [ts2068] ROM replacement services
Hi Mark,
You're right, the switched ROM would mean a toggle switch installed into the
case, although it could be left on a flying lead if you didn't want a hole
drilled into your TS2068. I'm still ascertaining costs, but I'd estimate
that the switched ROM installation would take about twice the length of time
as the single ROM.
I've done some preliminary investigations, involving discussions with Jarek
(to whom I owe a great deal of thanks) and taking apart every single one of
my Timex Sinclair 2068s (six of them) and Timex Computer 2068s (two). It
seems the mod can be done more easily for the American TS2068 than for the
Portuguese TC2068.
There is a fair degree of choice available for different ROM modifications.
I will summarise these and suggest recommended options (giving reasoning) on
a web page for the service.
Richard
9. Re: ROM replacement services - FlashD0
Jarek Adamski · Wed, 09 May 2007 23:19
Hello!
I've just translated the description of functionality
of FlashD0 upgrade for ZX Spectrum and Timex computers.
http://8bit.yarek.pl/upgrade/zx.flashd0/info-en.html
The FlashD0 board replaces the 16kB ROM and requires
3 extra signals to be connected with wires (/WR,
/IORQ, /RESET). Please consider it while upgrading
the ROM. :)
Using both 2068 mode and ZX128 mode on one machine
requires also a multiplexer like 74LS153 or 74LS157.
The ZX128 mode inside TS2068 requires also RAM upgrade.
I still work on ZX4MB dedicated for Timex.
ZXVGS FD0, except the FlashD0 upgrade, requires a
16kB RAM in last 16kB of memory. TC2144 upgrade or
Dock RAM cartridge are OK.
In case you could translate the text to better English
or correct my errors, please contact me directly to
my e-mail. If I could explain something, please mail
to the ts2068 group. :)
Have a good time.
Indexed under
TS2068 / TC2068 · Pico / modern interfaces (UnoDos, etc.) · Repair & restoration · Hardware projects & new boards