8 Apr
2004
8 Apr
'04
7:10 p.m.
In message <m1BBja8-000JAXC@p850ug1>
ard(a)p850ug1.demon.co.uk (Tony Duell) wrote:
The PSU problem I mentioned was actually due (as ever)
to dried-up
electrolytics on the output side of the PSU. Yes, I ended up having to
fix it...
Ugh. I've got an Acorn A4 power supply - I swapped out all the
electrolytics,
but it's still pretty knackered. It works fine until you try and boot the
laptop off it - if the battery is dead, the PSU "flutters" on and off
rapidly. Very strange. What really annoys me is that Acorn considered the PSU
to be a "non-serviceable unit", so no schematics exist :-(
Speaking of which, I still need to get my Jupiter Ace back (and fix it).
At least I've got schematics for it. Failing that I suppose I could build a
clone - shouldn't be too hard.
I used to use 3MHz xtals (available from RS
components). Gave a somewhat
low-pitched output, but it was useable. Most SPO256s will work at
3.2768MHz, which is another easy-to-find xtal frequency. Finding 3.12MHz
xtals was almost imposible in my experience...
I contacted a crystal manufacturer
that did a lot of work for radio hams
(custom crystals and the like) - they quoted me ?18 + VAT for a 3.12MHz
crystal. Eek. At least 3.2768 is a standard value...
I have at least one CTS256 chip in stock. This is a
programmed
microctroller (TMS7000/PIC7000 series IIRC) that connects to an SPO256
and which does text-to-speech conversions. It takes a serial or parallel
ASCII input IIRC.
Yep, I've heard of the CTS256. What I want is the
text-to-speech algorithm,
so I can program a PIC16F628 to replace a CTS256.
I will admit one thing though - I'd love to know what the General Instruments
LA05-148 is. I've got four SP0256A-AL2 "Narrator Speech Synth" ICs, four
LA05-148s (no idea what they are) and four R09864CS-2030s ("(C) CURRAH
1984"). I guess the R09864CS is a ROM, I know the SP0256 is a speech synth,
but I'll be damned if I can find any info on the LA05.
Later.
--
Phil. | Acorn Risc PC600 Mk3, SA202, 64MB, 6GB,
philpem(a)dsl.pipex.com | ViewFinder, 10BaseT Ethernet, 2-slice,
http://www.philpem.dsl.pipex.com/ | 48xCD, ARCINv6c IDE, SCSI
... Ancient Greeks made dolphin-killing punishable by death.