[time-nuts] Wanted - Service Manual for Solartron 7150+ DMM

Philip Pemberton lists at philpem.me.uk
Tue Jul 21 12:01:08 UTC 2009


David C. Partridge wrote:
> As and when you get a chance to look and if you find it I will be
> interested.

Still arguing with the bootloader on my Windows/Linux box, 
unfortunately. It'll boot Linux more than happily, but GRUB's 
"chainloader" isn't passing control over to the XP bootloader properly. Ugh.

> There are a few differences on the floating board - different uP and a few
> other differences.  The uC is an HD637B01V0P which is a one time
> programmable uC. Can be replaced with UV erasable HD637B01V0C if you can
> find on that is (hen's teeth).

Huh. Didn't spot one of those when I last had mine open (to clean up the 
mess from, and replace an incendiary mains filter), but then again I 
wasn't looking specifically at the floating board.

Though truth be told, if you had a copy of the ROM contents for that 
thing, you could replace it with an FPGA and a few other bits on a 
"bodge board". Most of the "other bits" would be related to 
bootstrapping the FPGA (basically you'd need a serial config ROM, e.g. 
an Altera EPCS or Xilinx Platform Flash) and running the oscillator.

You're probably talking £5 FPGA + (maybe) a cheap ROM + £2 worth of 74xx 
logic (level translators + oscillator) and a PCB. Maybe £30 total parts, 
less if you built the PCB yourself.

I dumped the main ROM from the controller board *years* ago; it's on 
Bruce Lane's FTP archive (ftp.bluefeathertech.com) under 
electronics/testgear/solartron/firmware. That's a 27128, and not hard to 
replace.

What's actually wrong with your 7150+?

> If you make an appropriately wired adapter from 40 pin to 28 pin I think you
> could probably read the internal ROM as if 27256.

Probably. Is it soldered down?

The datasheet doesn't mention any form of security / code protection, 
which is nice... :)
Reading out the ROM shouldn't be a problem at all -- replacing the chip 
on the other hand...

-- 
Phil.
lists at philpem.me.uk
http://www.philpem.me.uk/



More information about the time-nuts mailing list