P70 and TI 486 CPU

[SteffenU]

Hi all,

in my quest to improve my old P70, I ran across the Cyrix / TI upgrade
CPUs. I could source one for relatively cheap, it is the following CPU:
TX486DLC/E040C-GA. I am waiting for the confirmation whether it is the
BGA 132 Socket variant. Of course, it is a 40 MHz CPU, and my P70 is a
20MHz Model. Would that CPU run with the slower clock speed? I am likely
to buy it and just try it out.

This one would be even nicer with the 8kb Cache: Ti486 SXL-40 40MHz.
Would that run in my 20Mhz machine?

I am truly impressed about the vast information available for these
machines.

Cheers/2

[Kevin Bowling]

Post by SteffenU
Hi all,
in my quest to improve my old P70, I ran across the Cyrix / TI upgrade
TX486DLC/E040C-GA. I am waiting for the confirmation whether it is the
BGA 132 Socket variant.  Of course, it is a 40 MHz CPU, and my P70 is a
20MHz Model. Would that CPU run with the slower clock speed? I am likely
to buy it and just try it out.
This one would be even nicer with the 8kb Cache: Ti486 SXL-40 40MHz.
Would that run in my 20Mhz machine?
I am truly impressed about the vast information available for these
machines.
Cheers/2

I have had success with the Cyrix 40mhz 486 upgrade chip on the P70.

[SteffenU]

Hi,

great news, so I will try the TI chips, hopefully I find one of 8kb
variant. Did you change the quartz also? This would be a bit beyond me.

Cheers/2

Post by Kevin Bowling

Post by SteffenU
Hi all,
in my quest to improve my old P70, I ran across the Cyrix / TI upgrade
TX486DLC/E040C-GA. I am waiting for the confirmation whether it is the
BGA 132 Socket variant.  Of course, it is a 40 MHz CPU, and my P70 is
a 20MHz Model. Would that CPU run with the slower clock speed? I am
likely to buy it and just try it out.
This one would be even nicer with the 8kb Cache: Ti486 SXL-40 40MHz.
Would that run in my 20Mhz machine?
I am truly impressed about the vast information available for these
machines.
Cheers/2

I have had success with the Cyrix 40mhz 486 upgrade chip on the P70.

[Kevin Bowling]

Post by SteffenU
Hi,
great news, so I will try the TI chips, hopefully I find one of 8kb
variant. Did you change the quartz also? This would be a bit beyond me.

I did not change the oscillator yet, it will run at a lower speed but
with the new instructions and cache without doing so.

Post by SteffenU
Cheers/2

Post by Kevin Bowling

Post by SteffenU
Hi all,
in my quest to improve my old P70, I ran across the Cyrix / TI
upgrade CPUs. I could source one for relatively cheap, it is the
TX486DLC/E040C-GA. I am waiting for the confirmation whether it is
the BGA 132 Socket variant.  Of course, it is a 40 MHz CPU, and my
P70 is a 20MHz Model. Would that CPU run with the slower clock speed?
I am likely to buy it and just try it out.
This one would be even nicer with the 8kb Cache: Ti486 SXL-40 40MHz.
Would that run in my 20Mhz machine?
I am truly impressed about the vast information available for these
machines.
Cheers/2

I have had success with the Cyrix 40mhz 486 upgrade chip on the P70.

[Kevin Bowling]

Post by Kevin Bowling

Post by SteffenU
Hi,
great news, so I will try the TI chips, hopefully I find one of 8kb
variant. Did you change the quartz also? This would be a bit beyond me.

I did not change the oscillator yet, it will run at a lower speed but
with the new instructions and cache without doing so.

Oh I used the Cx486DRx2 which is internally clock doubled so no
oscillator change necessary.

There is some generic info on this family of Cyrix chips at
https://www.ardent-tool.com/CPU/Cyrix_Cx486.html

Post by Kevin Bowling

Post by SteffenU
Cheers/2

Post by Kevin Bowling

Post by SteffenU
Hi all,
in my quest to improve my old P70, I ran across the Cyrix / TI
upgrade CPUs. I could source one for relatively cheap, it is the
TX486DLC/E040C-GA. I am waiting for the confirmation whether it is
the BGA 132 Socket variant.  Of course, it is a 40 MHz CPU, and my
P70 is a 20MHz Model. Would that CPU run with the slower clock
speed? I am likely to buy it and just try it out.
This one would be even nicer with the 8kb Cache: Ti486 SXL-40 40MHz.
Would that run in my 20Mhz machine?
I am truly impressed about the vast information available for these
machines.
Cheers/2

I have had success with the Cyrix 40mhz 486 upgrade chip on the P70.

[SteffenU]

And I noticed you have an MCA PCMCIA Board, wow, didn't know that exists.

Post by Kevin Bowling

Post by SteffenU
Hi all,
in my quest to improve my old P70, I ran across the Cyrix / TI upgrade
TX486DLC/E040C-GA. I am waiting for the confirmation whether it is the
BGA 132 Socket variant.  Of course, it is a 40 MHz CPU, and my P70 is
a 20MHz Model. Would that CPU run with the slower clock speed? I am
likely to buy it and just try it out.
This one would be even nicer with the 8kb Cache: Ti486 SXL-40 40MHz.
Would that run in my 20Mhz machine?
I am truly impressed about the vast information available for these
machines.
Cheers/2

I have had success with the Cyrix 40mhz 486 upgrade chip on the P70.

[Kevin Bowling]

Post by SteffenU
And I noticed you have an MCA PCMCIA Board, wow, didn't know that exists.

These are mostly a curiosity and the card software support is not great.
You are effectively getting a 16-bit ISA bus out of PCMCIA so better
off going 32-bit MCA wherever possible.

One past curious use is PCMCIA sound cards, but a good one is now more
rare than MCA sound cards. Note that CardBus (i.e. Creative AudigyZS)
is 32-bit PCI-based and will not work.

There are new recreation MCA soundcards and CF/IDE adapters
(https://zzxio.com/product/mcide-cf/).

Post by SteffenU

Post by Kevin Bowling

Post by SteffenU
Hi all,
in my quest to improve my old P70, I ran across the Cyrix / TI
upgrade CPUs. I could source one for relatively cheap, it is the
TX486DLC/E040C-GA. I am waiting for the confirmation whether it is
the BGA 132 Socket variant.  Of course, it is a 40 MHz CPU, and my
P70 is a 20MHz Model. Would that CPU run with the slower clock speed?
I am likely to buy it and just try it out.
This one would be even nicer with the 8kb Cache: Ti486 SXL-40 40MHz.
Would that run in my 20Mhz machine?
I am truly impressed about the vast information available for these
machines.
Cheers/2

I have had success with the Cyrix 40mhz 486 upgrade chip on the P70.