Fastest "Turbo XT"

Discussion about old PC hardware.

Re: Fastest "Turbo XT"

Postby Scali » 2017-11-30 @ 20:26

As far as I know, officially there are no 8088 or V20 CPUs that are rated higher than 10 MHz.
The fastest 'common' variation of turbo XTs is 9.54 MHz (double that of the original PC).
I do vaguely recall however that there were some 'factory-overclocked' XT clones of 12 or 12.5 MHz. But I can't name any brands or models, so I may be mistaken.

Edit:
Apparently this might be such a board: https://th99.bl4ckb0x.de/m/A-B/32279.htm
Scali
l33t
 
Posts: 3421
Joined: 2014-12-13 @ 14:24

Re: Fastest "Turbo XT"

Postby konc » 2017-12-01 @ 08:25

Scali wrote:As far as I know, officially there are no 8088 or V20 CPUs that are rated higher than 10 MHz.

I've got some cheap V20s bought from an ebay Chinese seller that are rated for 16MHz. Of course I don't own anything that can go beyond 10MHz to try them, so I only know that they work at 10MHz.

But despite my doubts for these specific chips, it is a fact that NEC officially produced V20s rated higher than 10MHz. I never encountered a PC/XT using one at full speed though, maybe they were targeting different platforms?
User avatar
konc
Oldbie
 
Posts: 934
Joined: 2013-1-14 @ 15:09
Location: Greece

Re: Fastest "Turbo XT"

Postby Kubik » 2017-12-01 @ 08:58

Scali wrote:As far as I know, officially there are no 8088 or V20 CPUs that are rated higher than 10 MHz.

There are HL variants of V20 and V30 rated up to 16MHz.
Kubik
Member
 
Posts: 140
Joined: 2017-11-06 @ 08:24

Re: Fastest "Turbo XT"

Postby harddrivespin » 2017-12-01 @ 09:57

Good to know, thanks!
User avatar
harddrivespin
Member
 
Posts: 134
Joined: 2017-8-16 @ 20:36

Re: Fastest "Turbo XT"

Postby Scali » 2017-12-01 @ 11:12

Kubik wrote:
Scali wrote:As far as I know, officially there are no 8088 or V20 CPUs that are rated higher than 10 MHz.

There are HL variants of V20 and V30 rated up to 16MHz.


It seems you are right, here is the datasheet (I had only looked at the regular V20 before):
http://html.alldatasheet.com/html-pdf/1 ... 10-22.html

The uDP70108HCZ-16 would be the 16 MHz version that is pin-compatible with a 8088.
There is also a 12.5 MHz version.
Scali
l33t
 
Posts: 3421
Joined: 2014-12-13 @ 14:24

Re: Fastest "Turbo XT"

Postby dr.ido » 2017-12-01 @ 13:40

The V40 was used in some laptops. I had a sharp laptop with one. I don't remember it being any faster than a V30 based desktop, so I think the V40 was more a low power/cost saving option than a performance part. Any other Australian here remember the micron pc300 (I may have the name wrong, it's been a long time) - small form factor PC before SFF was a thing, 10MHz V30. What made is special and faster than most other XT class systems was the onboard EGA and SCSI also ran at 10MHz...
dr.ido
Newbie
 
Posts: 38
Joined: 2017-12-01 @ 12:55

Re: Fastest "Turbo XT"

Postby Kubik » 2017-12-01 @ 13:46

As for all the NEC Vxx stuff, Wiki covers it well: https://en.wikipedia.org/wiki/NEC_V20 :)
I recommend reading it, a lot of interesting stuff!
Kubik
Member
 
Posts: 140
Joined: 2017-11-06 @ 08:24

Re: Fastest "Turbo XT"

Postby Anonymous Coward » 2017-12-01 @ 14:07

One of the most interesting of the NEC V series is the V33A. It can address up to 16MB like a 286. Unfortunately, I don't know that it was ever used in a PC. It's not a 286 clone, and I don't think it has a protected mode.

BTW, according to that wiki page, the Vadem VG330 (a portable?) has a V30MX running at 32MHZ!
Will the highways on the internets become more few?
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium
User avatar
Anonymous Coward
l33t
 
Posts: 2752
Joined: 2008-3-20 @ 05:37
Location: Shandong, China

Previous

Return to General Old Hardware

Who is online

Users browsing this forum: Baidu [Spider] and 9 guests