12 Mar
2013
12 Mar
'13
6:19 p.m.
Idle curiousity, does anyone happen to know whether the TMS4100 ROM
was a standard off-the-shelf character generator from TI, or was it a
generic mask-ROM-to-customer-order, or otherwise have data on it such
as it's native size.
Full id:
TMS4100
ZA 5705
T-04163
7308 <-- date code
It's the character generator in the HP9830, arranged for character
column scanning order rather than row scanning (7-bits columns at the
outputs rather than 5-bit rows).
I see three possibilities:
- the TI TMS4100 is a character generator ROM
- it's a TI TMS 4100 mask ROM, programmed and sold by TI as a
character gen
- it's a TI TMS 4100 mask ROM, programmed to order for HP
I've sorted out the pinout, so it's not a dire need, just curious.
13 Mar
13 Mar
2:04 p.m.
Idle curiousity, does anyone happen to know whether the TMS4100 ROM
was a standard off-the-shelf character generator from TI, or was it a
generic mask-ROM-to-customer-order, or otherwise have data on it such
as it's native size.
The 1976 'Memroy and Microprocessor Databook' (Texas Instruemnts) lists a
TMS4102 Cheracter Gerneator. Like the one in the HP9830, it reads out a
column at a time, and has the same pinout. I will give the pinout fro
mthe databook in a minute. The difference seems to be that the TMS4103
is specified as having 'Inputs and Outputs Fully TTL compatible) while
the inputs o ntne TMS4100 seem to be 12V levels. The HP9830 Dispaly
Driver PCB (09830-66542) drives them with high voltabge open-collector
buffers ('145 and '07), pulled up to 12V via a 1k2 resistor.
Anyway, the pinout of the TMS4103 (and I used this when
reverse-engineering the HP9830) is :
-----
O1 -| U |- I7
NC -| |- I1
O2 -| |- I2
NC -| |- I3
O3 -| |- I4
NC -| |- I5
O4 -| |- CE
NC -| |- CD
O5 -| |- CC
NC -| |- CB
O6 -| |- CA
NC -| |- Vss
O7 -| |- I6
Vdd -| |- Vgg
-----
Where : I1-I6 = Binary-encoded chracter inputs (64 different chracters)
I7 = Chip eneable input (active high)
CA-CE = Column select inputs, 1-of-5 encoded
O1-O7 = Data output
Vdd,Vss,Vgg = power/ground/bias
Unforutnately there is only 1 page of data on it in the book and it
doesn't give the paterns for the characters. The data sheet is dated May
1975 (after hte design of the HP9830, of course).
Full id:
TMS4100
ZA 5705
T-04163
7308 <-- date code
It's the character generator in the HP9830, arranged for character
column scanning order rather than row scanning (7-bits columns at the
outputs rather than 5-bit rows).
I see three possibilities:
- the TI TMS4100 is a character generator ROM
- it's a TI TMS 4100 mask ROM, programmed and sold by TI as a
character gen
- it's a TI TMS 4100 mask ROM, programmed to order for HP
My _guess_ is that the TMS4100 is a standrd character generator ROM and the
TSM4103 is an imporved version with TTL-compatible inputs.
The ratehr odd address inpout (1-of-5 colum select, for example) seems to
suggst it's not a standard ROM device (I would epxpect fully bianry coded
address inputso n such a device).
If yuo need to replace it, do watch for those 12V levels. it's very easy
to covert abck to 5V levels, (jsut change where the pull-ups go to) but you
may not want to make too many changes to the board.
-tony
6:38 p.m.
On 2013 Mar 13, at 2:04 PM, Tony Duell wrote:
<snip>
(I had the pinout)
Idle curiousity, does anyone happen to know whether the TMS4100 ROM
was a standard off-the-shelf character generator from TI, or was it a
generic mask-ROM-to-customer-order, or otherwise have data on it such
as it's native size.
The 1976 'Memroy and Microprocessor Databook' (Texas Instruemnts)
lists a
TMS4102 Cheracter Gerneator. Like the one in the HP9830, it reads
out a
column at a time, and has the same pinout. I will give the pinout fro
mthe databook in a minute. The difference seems to be that the
TMS4103
is specified as having 'Inputs and Outputs Fully TTL compatible) while
the inputs o ntne TMS4100 seem to be 12V levels. The HP9830 Dispaly
Driver PCB (09830-66542) drives them with high voltabge open-collector
buffers ('145 and '07), pulled up to 12V via a 1k2 resistor. Unforutnately there is only 1 page of data on it in
the book and it
doesn't give the paterns for the characters. The data sheet is
dated May
1975 (after hte design of the HP9830, of course).
Another list member (Rob) found the ref in a 1970/1 TI book.
Apparently, it's part of a character generator series, the 4103 is
the off-the-shelf standard ASCII version in the series.
As Rob pointed out, the 9830 one must be special order to HP though,
to obtain the lazy-T cursor, unless there's some alternative tortured
way they're injecting the T into the display scanning that I'm not
seeing.
Yes, the-1-of-5 select did suggest it was an intended character
generator (although in principle it could be a straight ROM depending
upon how much ROM space one is willing to waste, although (back on
the other hand) being that wasteful would have been pushing it for
ROM sizes of the period, and the 9830 has the binary encoding right
there anyways).
The earlier data only indicates MOS levels (for TMS 4103 JC/NC).
Full id:
TMS4100
ZA 5705
T-04163
7308 <-- date code
It's the character generator in the HP9830, arranged for character
column scanning order rather than row scanning (7-bits columns at the
outputs rather than 5-bit rows).
I see three possibilities:
- the TI TMS4100 is a character generator ROM
- it's a TI TMS 4100 mask ROM, programmed and sold by TI as a
character gen
- it's a TI TMS 4100 mask ROM, programmed to order for HP
My _guess_ is that the TMS4100 is a standrd character generator ROM
and the
TSM4103 is an imporved version with TTL-compatible inputs.
The ratehr odd address inpout (1-of-5 colum select, for example)
seems to
suggst it's not a standard ROM device (I would epxpect fully bianry
coded
address inputso n such a device).
..
14 Mar
14 Mar
2:52 p.m.
(I had the pinout)
Sure, but others might not have...
Another list member (Rob) found the ref in a 1970/1 TI book.
Apparently, it's part of a character generator series, the 4103 is
the off-the-shelf standard ASCII version in the series.
Right...
As Rob pointed out, the 9830 one must be special order to HP though,
to obtain the lazy-T cursor, unless there's some alternative tortured
As I seaid, the data sheet i have doesn't give the font pattern, so I
didn't know i the 'lazy T' was a standard cahracter or not.
way they're injecting the T into the display
scanning that I'm not
seeing.
There isn't, AFAIK.
The HP9830 display is ratehr differnet to that in the other 9800 machiens
in that it is partly hardware driven.
The CPU has a 16 bit shift regiater used for I/O (it's on the 09810-66511
PCB). When drivign the dispaly, al l16 bits are used for data, a separate
circuit genrates a strobe signal. Now, the HP9830 has a 32 character
display and the hardare dispalys 2 characters simultaneously, 16
locations apart (so 0 and 16, 1 and 17, etc). The 16 bits are used as
follows :
6 bits for the code of one of the characters (remember upper case only,
so 64 characters is enough)
6 bits for the code of the other chracter
4 bits to select where to put them (location of theleft hand character).
But the system firmware has to scan all 16 pairs of locations, otuputting
the right character codes.
There is, AFAIK, no way to dispaly anything otehr tha nthe patterns in
the chracter genrator.
One other trap fo the unwary. The display is physically a 32 chracter 5*7
dot matrix unit. That is, 160 columns by 7 rows. _Electrically_ it's
wired as 0 columns by 28 rows, this saves driver stages. Therefore
drfectinve row drivers stages will affect only part of a dot row and
defective column drivers will affect 4 colunmns on the display.
Yes, the-1-of-5 select did suggest it was an intended character
generator (although in principle it could be a straight ROM depending
upon how much ROM space one is willing to waste, although (back on
the other hand) being that wasteful would have been pushing it for
ROM sizes of the period, and the 9830 has the binary encoding right
there anyways).
At the time yo did not wast 27/32 of your ROM capactiy. You might now,m
if you had to repalce the chracter gernatore, but back then you used
verybit you had. Yo ucertianly didn't add a decoder to waste ROM space ;-)
The earlier data only indicates MOS levels (for TMS 4103 JC/NC).
Interesting. My databook cleaerly says 'fully TTL compatible' whih I take
to mean 5V levels (and not that you can drive it with open-collector 74xx
parts pulled up to 12V).
Whether the later versions could stand 12V on the inputs I don't know.
-tony
4301
days inactive
4302
days old
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hilpert＠cs.ubc.ca