Skip to content

Convert TS2068 into ZX Spectrum 128K

8 messages · 2008-06-22 → 2008-07-03 · Yahoo Group era · View archive on archive.org

Participants: zxbruno, Jarek Adamski, Don Dindang, Jim Delaney

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. Convert TS2068 into ZX Spectrum 128K

zxbruno · Sun, 22 Jun 2008 13:53

I've seen two references to this type of upgrade, all internal.

One is from an italian website, but there's no info besides a picture:

http://www.zxspectrum.it/images/REB_128.jpg

And one is from Yarek's website, where it explains how to upgrade a
Spectrum 48K or a Timex TC2048 to a 128K computer.

http://8bit.yarek.pl/upgrade/zx.to128k/index.html

This is not for those who say it's too complicated, not worth it, etc.
It's for those who wanted to know if it was possible or not.

2. Re: Convert TS2068 into ZX Spectrum 128K

Jarek Adamski · Mon, 23 Jun 2008 23:04

Hello!

I've upgraded several Timex Computer 2068 to ZX Spectrum 128K
compatibility. The upgrade board was mounted over SCLD chip,
so this is not compatibile to TS268. However, one upgrade
was done by direct soldering to TC2048 board, so this is
also possible on TS2068.
http://8bit.yarek.pl/upgrade/zx.tc2144/index.html

And the picture with the upgrade board opened:
http://8bit.yarek.pl/upgrade/zx.tc2144/0007-toq.jpg


My second solution was 4MB RAM + 128kB PEROM, by default
for ZX Spectrum Issue 6A, but I mounted one inside TC2048.
Unfortunately, I have a problem with second screen
stability, so the project is unfinished. Once I get the
solution to get both screens stable, I'm going to design
a 4MB RAM board to be placed under Z80CPU, rather than
in place of 4132 memories in ZX Spectrum.
http://8bit.yarek.pl/upgrade/zx.zx4mb/index.html


The ZX128 compatibility is not possible without internal
changes, mostly due to the second screen feature. In TS2068
there's also problem with NTSC, that reduces Z80CPU tacts
per screen frame.

Jarek Adamski

3. Re: Convert TS2068 into ZX Spectrum 128K

zxbruno · Sat, 28 Jun 2008 22:51

--- In [email], "Jarek Adamski" <8bit@...> wrote:
>
> Hello!
> 
> I've upgraded several Timex Computer 2068 to ZX Spectrum 128K
> compatibility. The upgrade board was mounted over SCLD chip,
> so this is not compatibile to TS268. However, one upgrade
> was done by direct soldering to TC2048 board, so this is
> also possible on TS2068.
> http://8bit.yarek.pl/upgrade/zx.tc2144/index.html
> 
> And the picture with the upgrade board opened:
> http://8bit.yarek.pl/upgrade/zx.tc2144/0007-toq.jpg
> 
> 
> My second solution was 4MB RAM + 128kB PEROM, by default
> for ZX Spectrum Issue 6A, but I mounted one inside TC2048.
> Unfortunately, I have a problem with second screen
> stability, so the project is unfinished. Once I get the
> solution to get both screens stable, I'm going to design
> a 4MB RAM board to be placed under Z80CPU, rather than
> in place of 4132 memories in ZX Spectrum.
> http://8bit.yarek.pl/upgrade/zx.zx4mb/index.html
> 
> 
> The ZX128 compatibility is not possible without internal
> changes, mostly due to the second screen feature. In TS2068
> there's also problem with NTSC, that reduces Z80CPU tacts
> per screen frame.
> 
> Jarek Adamski
>

Hi Jarek!

No chance of doing everything by using an interface or a TS2068
cartridge then? If this is not possible maybe a small board that could
be soldered or placed inside the TS2068 would be a good idea.
Do you have a TS2068 to test it? If it's necessary I'll donate mine,
so that others can have (one day) a 128K-compatible TS2068.

I think the 4MB option is kinda overkill. The most important thing
would be compatibility with 128K games, memory paging and AY sound.

4. Re: Convert TS2068 into ZX Spectrum 128K

Jarek Adamski · Sun, 29 Jun 2008 11:07

Hello !

--- In [email], "zxbruno" wrote:
> No chance of doing everything by using an interface or a TS2068
> cartridge then?
To get the second screen you need to cut some tracks between
SCLD and its video memory.

> If this is not possible maybe a small board that could
> be soldered or placed inside the TS2068 would be a good idea.
I'm thinking of such board, mounted into Z80CPU socket to
reduce number of extra wires needed, since I made the
board for ZX Spectrum Issue 6A in 2004...

> Do you have a TS2068 to test it?
Yes, I have one. Also some TC2068 and TC2048 are waitnig
for memory upgrade.

> I think the 4MB option is kinda overkill.
I wanted to get compatibility with Russian Pentagon 512kB.
Then, the smallest memory I could use was 1MB DRAM (two
chips 4b×1M). But the logic needed for 1MB is the same
as for 4MB: two bank number bit latches and one multiplexer
are mounted anyway. So finally I used two 4b×4M DRAM chips.
Therea are only several more tracks on the board.

> The most important thing would be compatibility with 128K
> games, memory paging and AY sound.
The 4MB DRAM is fully compatibile with Spectrum 128K.
It is seen in Home bank, so the Dock and EXROM are not
touched and can be used independly.

AY port mapping is separate thing and can be easy done.
I've remapped several times the AY in TC2068 to be
available both in 2068 and ZX128 mode (port addresses).

In matter of the ROM, the FlashD0 upgrade allows to use
two switchable ZX128 ROM banks, or one non-switchable
ZX48 ROM, or even can be used to fill 64kB EXROM (this
is still not tested, but included in the idea).


One problem with the upgrade is using the #F4 port. After
upgrade, both screens must be accessed in section B
(A14_SCLD=1, A15_SCLD=0), so this corresponds always with
bits 3 and 4 of the #F4 port, independly on the addresses
the screens are located (at #4000 or at #C000). To keep
the function of #F4 register it must be duplicated with
extra logic, while the one build-in SCLD gets useless.


I can design the boards and describe the upgrade process,
but would need someone in U.S., who could install them.


Jarek Adamski

5. Re: [ts2068] Re: Convert TS2068 into ZX Spectrum 128K

Don Dindang · Sun, 29 Jun 2008 09:02

Hi,
I'm in the US, wiling to install and try that board.

Watchara

--- On Sun, 6/29/08, zxbruno <[email]> wrote:
From: zxbruno <[email]>
Subject: [ts2068] Re: Convert TS2068 into ZX Spectrum 128K
To: [email]
Date: Sunday, June 29, 2008, 8:38 AM











            --- In ts2068@yahoogroups. com, "Jarek Adamski" <8bit@...> wrote:



> I can design the boards and describe the upgrade process,

> but would need someone in U.S., who could install them.



This is the tricky part. If I ask in WOS or Speccy.org I'm sure

someone in the U.K. or Spain will be happy to help, but in the U.S. I

don't know anyone who has the time, will and knowledge to do it.



There's an interesting fact about the Timex computers - They're more

popular in Spain and Poland than they ever were here in the U.S. or

even in Portugal! In Poland we have you and others who have designed

incredible upgrades and keep using the TC2048 and TC2068 as much as

you used to 20 years ago. There's also a musician called Yerzmyey who

uses a TC2048 with an AY-interface and composes incredible 3-channel

music. In Spain we have Jose Manuel who hosts software for TC and TS

computers and he now has several TS2068 cartridges preserved as .dck

files thanks to the cartridge reader created by Jose Leandro! I can't

thank these people enough for keeping the Timex alive.



If no one in the group offers to install it for you, I'll start asking

and I'm sure I'll find someone in Europe. It may take a few years

until I learn the basics of electronics.

6. Re: Convert TS2068 into ZX Spectrum 128K

zxbruno · Sun, 29 Jun 2008 15:38

--- In [email], "Jarek Adamski" <8bit@...> wrote:

> I can design the boards and describe the upgrade process,
> but would need someone in U.S., who could install them.

This is the tricky part. If I ask in WOS or Speccy.org I'm sure
someone in the U.K. or Spain will be happy to help, but in the U.S. I
don't know anyone who has the time, will and knowledge to do it.

There's an interesting fact about the Timex computers - They're more
popular in Spain and Poland than they ever were here in the U.S. or
even in Portugal! In Poland we have you and others who have designed
incredible upgrades and keep using the TC2048 and TC2068 as much as
you used to 20 years ago. There's also a musician called Yerzmyey who
uses a TC2048 with an AY-interface and composes incredible 3-channel
music. In Spain we have Jose Manuel who hosts software for TC and TS
computers and he now has several TS2068 cartridges preserved as .dck
files thanks to the cartridge reader created by Jose Leandro! I can't
thank these people enough for keeping the Timex alive.

If no one in the group offers to install it for you, I'll start asking
and I'm sure I'll find someone in Europe. It may take a few years
until I learn the basics of electronics.

7. Re: Convert TS2068 into ZX Spectrum 128K

zxbruno · Mon, 30 Jun 2008 02:54

Great news! I look forward to see the development of this project!

--- In [email], Don Dindang <kmitl22@...> wrote:
>
> Hi,
> I'm in the US, wiling to install and try that board.
> 
> Watchara
> 
> --- On Sun, 6/29/08, zxbruno <zxspectrum128@...> wrote:
> From: zxbruno <zxspectrum128@...>
> Subject: [ts2068] Re: Convert TS2068 into ZX Spectrum 128K
> To: [email]
> Date: Sunday, June 29, 2008, 8:38 AM
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
>     
>             --- In ts2068@yahoogroups. com, "Jarek Adamski" <8bit@>
wrote:
> 
> 
> 
> > I can design the boards and describe the upgrade process,
> 
> > but would need someone in U.S., who could install them.
> 
> 
> 
> This is the tricky part. If I ask in WOS or Speccy.org I'm sure
> 
> someone in the U.K. or Spain will be happy to help, but in the U.S. I
> 
> don't know anyone who has the time, will and knowledge to do it.
> 
> 
> 
> There's an interesting fact about the Timex computers - They're more
> 
> popular in Spain and Poland than they ever were here in the U.S. or
> 
> even in Portugal! In Poland we have you and others who have designed
> 
> incredible upgrades and keep using the TC2048 and TC2068 as much as
> 
> you used to 20 years ago. There's also a musician called Yerzmyey who
> 
> uses a TC2048 with an AY-interface and composes incredible 3-channel
> 
> music. In Spain we have Jose Manuel who hosts software for TC and TS
> 
> computers and he now has several TS2068 cartridges preserved as .dck
> 
> files thanks to the cartridge reader created by Jose Leandro! I can't
> 
> thank these people enough for keeping the Timex alive.
> 
> 
> 
> If no one in the group offers to install it for you, I'll start asking
> 
> and I'm sure I'll find someone in Europe. It may take a few years
> 
> until I learn the basics of electronics.
>

8. Re: [ts2068] Re: Convert TS2068 into ZX Spectrum 128K

Jim Delaney · Thu, 3 Jul 2008 14:13:

--- On Sun, 29/6/08, Don Dindang <[email]> wrote:
From: Don Dindang <[email]>
Subject: Re: [ts2068] Re: Convert TS2068 into ZX Spectrum 128K
To: [email]
Date: Sunday, 29 June, 2008, 5:02 PM











            Hi,
I'm in the US, wiling to install and try that board.

Watchara

--- On Sun, 6/29/08, zxbruno <zxspectrum128@ gmail.com> wrote:
From: zxbruno <zxspectrum128@ gmail.com>
Subject: [ts2068] Re: Convert TS2068 into ZX Spectrum 128K
To: ts2068@yahoogroups. com
Date: Sunday, June 29, 2008, 8:38 AM








            --- In ts2068@yahoogroups. com, "Jarek Adamski" <8bit@...> wrote:



> I can design the boards and describe the upgrade process,

> but would need someone in U.S., who could install them.



This is the tricky part. If I ask in WOS or Speccy.org I'm sure

someone in the U.K. or Spain will be happy to help, but in the U.S. I

don't know anyone who has the time, will and knowledge to do it.



There's an interesting fact about the Timex computers - They're more

popular in Spain and Poland than they ever were here in the U.S. or

even in Portugal! In Poland we have you and others who have designed

incredible upgrades and keep using the TC2048 and TC2068 as much as

you used to 20 years ago. There's also a musician called Yerzmyey who

uses a TC2048 with an AY-interface and composes incredible 3-channel

music. In Spain we have Jose Manuel who hosts software for TC and TS

computers and he now has several TS2068 cartridges preserved as .dck

files thanks to the cartridge reader created by Jose Leandro! I can't

thank these people enough for keeping the Timex alive.



If no one in the group offers to install it for you, I'll start asking

and I'm sure I'll find someone in Europe. It may take a few years

until I learn the basics of electronics.










Hi guys, thought you all might like to see my Z80A 4Mhz USB Peripheral, Did it all myself:
http://uk.geocities.com/slot_racing/control/pc_driven.htm
hope you like it ;-)
cheers, Jim


 




















      __________________________________________________________
Not happy with your email address?.
Get the one you really want - millions of new email addresses available now at Yahoo! http://uk.docs.yahoo.com/ymail/new.html

Indexed under

TS2068 / TC2068 · ZX Spectrum · Hardware projects & new boards