I can get lots of TI 99 items, tell what you are looking for ??
At 10:28 AM 8/18/97 BST, you wrote:
>> > I bought: A TI-99/4A (Not as lucky as Roger M - I paid L12 with no
>> > joysticks, manuals or cartridges, but I did get the UHF thingy)
>>
>> Nice!!!....
>
>Yes, my first TI computer (I have a broken calculator and a Silent 700
>or two...)
>
>> > But the real find: A British Telecom Microscribe for L1
>>
>> Very nice...
>>
>> > This object is a solidly built sub-notebook (about 7 in square by 1
>> > thick) with a dinky keyboard and a palmtop-sized LCD. It has 32K of RAM
>> > and 16K of ROM, and the processor is an Hitachi HD63A03XP single chip
>> > microcomputer.
>>
>> Is that the only processor? It sounds as though it might be distantly
>> related to a Thorn-EMI machine called a Liberator which had a 63-something
>> for I/O and a Z80 running a CP/M like OS (or at least, that what I think
>> is inside it - the ROM is (C) Digital Research, and running strings on a
>> ROM image turns up some interesting stuff)
>
>'fraid so. Indeed, it is the only chip with >28 pins (apart from the
>flatpacks on the back of the LCD). IC master, just to be perverse,
>gives various 6301 and 6305 variants in that series, but nothing of 6303
>flavour.
>
>> Not so. A lot of machines use the NiCd as the smoothing component. HP
>> certainly did in just about all of their more recent NiCd calculators (the
>> ones that use the 8V 50mA AC charger).
>
>Interesting. I haven't found where the battery gets in, but the input
>stage is something like:
>
> Diode
>Ring --+--/\/\/-|>|-+-----+
> | 56R | \
> | |C / 82R
> | |/ \
> +-/\/\/-+--| NPN /
> | |\ |
> _ |E |
>Tip--+ Zener A +-----+--- +5V? to rest of machine (??)
> | |
> GND GND
>
>I would guess the battery could well do any smoothing downstream of the
>regulator, but I'd still like to see some upstream of it!
>
>If the machine draws 60mA, minimum voltage at input is around 9V,
>maximum around 13V, so I suppose I could try 10V and see what happens...
>
>> Some, like the Epson HX20 even used the fact that the voltage across the
>> NiCd would go above 5V to limit the supply voltage to the chips. The
> ^^^^^
>I take it you mean wouldn't
>
>> If you have an adjustable PSU, apply about 5V, and then crank it up
>> towards 9V (I'd guess that's what it takes), monitor the 5V line and stop
>> if it rises above (say) 5.5V. See what current flows - it should be
>> arround 50mA.
>
>Worth a try.
>
>Philip.
>
>
>
Anyone want any Kaypro 10s? I know someone who has a couple he wants to
get rid of.
Sam
-------------------------------------------------------------------------------
Computer Historian, Programmer, Musician, Philosopher, Athlete, Writer, Jackass
Umm... I just noticed something. On the READY lamp, where the drive
number is supposed to be, mine is blank. There's nothing behind the ready
cover. No metal in it. Does that mean drive 0?
> I've got a little reference card for HP9830A Basic. Get me your postal
> address and I'll send you a copy.
Thank you, it looks as if I'll be unloading it. Perhaps he who gets it
would be interested.
[My ascii circuit diagram]
> That looks like a voltage regualtor, which is strange, since I'd have
> expected a constant current charger for the NiCd. Of course a lot of
> machines just use a resistor to limit the charging current (and to get you
> to buy more expensive battery packs)
It does to me, too! By "to get you to buy more expensive battery packs"
do you mean that the packs are more expensive, or that they wear out
faster?
> > If the machine draws 60mA, minimum voltage at input is around 9V,
> > maximum around 13V, so I suppose I could try 10V and see what happens...
>
> Remember that you'll be charging this thing (probably) with the machine
> turned off, so it's not going to be taking much current).
Good point. 50mA then (8 < V < 12) based on the 14 hour rate on the
battery label. Looks like 9V is about right...
There is also a power switch but I haven't found where it connects yet.
(Not in series with the circuit I just drew AFAIK) Next task, I
suppose, is to trace that part of the circuit. Difficult, because most
of PCB tracks are underneath LCD module which is difficult to remove...
Philip.
> > I bought: A TI-99/4A (Not as lucky as Roger M - I paid L12 with no
> > joysticks, manuals or cartridges, but I did get the UHF thingy)
>
> Nice!!!....
Yes, my first TI computer (I have a broken calculator and a Silent 700
or two...)
> > But the real find: A British Telecom Microscribe for L1
>
> Very nice...
>
> > This object is a solidly built sub-notebook (about 7 in square by 1
> > thick) with a dinky keyboard and a palmtop-sized LCD. It has 32K of RAM
> > and 16K of ROM, and the processor is an Hitachi HD63A03XP single chip
> > microcomputer.
>
> Is that the only processor? It sounds as though it might be distantly
> related to a Thorn-EMI machine called a Liberator which had a 63-something
> for I/O and a Z80 running a CP/M like OS (or at least, that what I think
> is inside it - the ROM is (C) Digital Research, and running strings on a
> ROM image turns up some interesting stuff)
'fraid so. Indeed, it is the only chip with >28 pins (apart from the
flatpacks on the back of the LCD). IC master, just to be perverse,
gives various 6301 and 6305 variants in that series, but nothing of 6303
flavour.
> Not so. A lot of machines use the NiCd as the smoothing component. HP
> certainly did in just about all of their more recent NiCd calculators (the
> ones that use the 8V 50mA AC charger).
Interesting. I haven't found where the battery gets in, but the input
stage is something like:
Diode
Ring --+--/\/\/-|>|-+-----+
| 56R | \
| |C / 82R
| |/ \
+-/\/\/-+--| NPN /
| |\ |
_ |E |
Tip--+ Zener A +-----+--- +5V? to rest of machine (??)
| |
GND GND
I would guess the battery could well do any smoothing downstream of the
regulator, but I'd still like to see some upstream of it!
If the machine draws 60mA, minimum voltage at input is around 9V,
maximum around 13V, so I suppose I could try 10V and see what happens...
> Some, like the Epson HX20 even used the fact that the voltage across the
> NiCd would go above 5V to limit the supply voltage to the chips. The
^^^^^
I take it you mean wouldn't
> If you have an adjustable PSU, apply about 5V, and then crank it up
> towards 9V (I'd guess that's what it takes), monitor the 5V line and stop
> if it rises above (say) 5.5V. See what current flows - it should be
> arround 50mA.
Worth a try.
Philip.
Hi there everyone!
I went to the car boot sale again yesterday. For once, there were lots
of computers on offer: two ZX Spectra (original 16K); one Spectrum +2;
an Atari 620; any number of Commodore 64s in late-style cases.
I bought: A TI-99/4A (Not as lucky as Roger M - I paid L12 with no
joysticks, manuals or cartridges, but I did get the UHF thingy)
But the real find: A British Telecom Microscribe for L1
This object is a solidly built sub-notebook (about 7 in square by 1
thick) with a dinky keyboard and a palmtop-sized LCD. It has 32K of RAM
and 16K of ROM, and the processor is an Hitachi HD63A03XP single chip
microcomputer.
THE LCD looks as if it might be 200 or 256 by 64 pixels (40 characters
by 8 lines?) - I haven't powered it up yet because (a) the NiCd battery
is flat and (b) I have yet to work out what voltage to feed it (3.5mm
jack with tip negative). All I know is that it must be smoothed DC,
since there is a diode but no smoothing capacitor in the input stage.
The battery is 4.8V, and somewhat inconsistently marked 0.8 Ah - charge
at 50mA for 14 hours (I make that 0.7Ah less charging losses), so the
power supply (which feeds a linear regulator - transistor in parallel
with 82 ohms) must be greater than this. I would guess at something in
the region of 9V given the size of the resistors in the regulator
circuit, but...
The manufacturer's label on the back suggests it is a Microscribe Model
320, made by Microscribe Ltd at Cwmbran in South Wales. Since they had
the forethought to put an address and 'phone number on the label, I
shall try and contact them this week (DV).
Meanwhile, does anyone have any info on this? In particular, what
voltage do I feed it?
Philip.
<><><><><><><><><><><><><><> Philip Belben <><><><><><><><><><><><><><>
Das Feuer brennt, das Feuer nennt die Luft sein Schwesterelement -
und frisst sie doch (samt dem Ozon)! Das ist die Liebe, lieber Sohn.
Poem by Christian Morgenstern - Message by Philip.Belben(a)powertech.co.uk
Anybody know what an Opus 5000 is? Someone offered me one for sale and
I'm trying to figure out how much I should offer to pay him for it. Thanks.
Sam
-------------------------------------------------------------------------------
Computer Historian, Programmer, Musician, Philosopher, Athlete, Writer, Jackass
