Discussion:
Videx vs chinesium videx clones
(too old to reply)
Jorge
2017-07-03 21:01:25 UTC
Permalink
Raw Message
I have a question:

Why is it that the Videx original only works in slot 3 but all the chinesium clones work in any slot? *Cn00L with the Videx gives garbage (but always the same garbage as if it was reading the wrong page into the ROM) for anything but slot n=3. I've got several videx and all of them do the same... Grrr !

Any ideas?

Thanks,
--
Jorge.
Michael J. Mahon
2017-07-04 16:29:09 UTC
Permalink
Raw Message
Post by Jorge
Why is it that the Videx original only works in slot 3 but all the
chinesium clones work in any slot? *Cn00L with the Videx gives garbage
(but always the same garbage as if it was reading the wrong page into the
ROM) for anything but slot n=3. I've got several videx and all of them do
the same... Grrr !
Any ideas?
Thanks,
Perhaps because slot 3 was already the "standard" slot for 80-column
output, the Videx firmware was written to assume residence in slot 3.

There is some penalty in code and complexity to make a card
slot-independent.
--
-michael - NadaNet 3.1 and AppleCrate II: http://michaeljmahon.com
Jorge
2017-07-04 19:03:01 UTC
Permalink
Raw Message
Post by Michael J. Mahon
Post by Jorge
Why is it that the Videx original only works in slot 3 but all the
chinesium clones work in any slot? *Cn00L with the Videx gives garbage
(but always the same garbage as if it was reading the wrong page into the
ROM) for anything but slot n=3. I've got several videx and all of them do
the same... Grrr !
Any ideas?
Thanks,
Perhaps because slot 3 was already the "standard" slot for 80-column
output, the Videx firmware was written to assume residence in slot 3.
There is some penalty in code and complexity to make a card
slot-independent.
If I put a chinese clone in slot 2 and an original Videx in slot 3 and do *C300<C200.C2FFV all bytes match ( if I recall correctly ).
David Schmenk
2017-07-04 18:31:09 UTC
Permalink
Raw Message
Post by Jorge
Why is it that the Videx original only works in slot 3 but all the chinesium clones work in any slot? *Cn00L with the Videx gives garbage (but always the same garbage as if it was reading the wrong page into the ROM) for anything but slot n=3. I've got several videx and all of them do the same... Grrr !
Any ideas?
Thanks,
--
Jorge.
Regardless wether the ROM was meant to work in slot 3 or not (I don't recall seeing any slot 3 specific code in the Video ROM), you should still be able to list it in the slot specific ROM address - assuming the qualify the ROM access with /IO-SELECT (can't imagine why they wouldn't). Do you still see the ROM at $C300 even when it's plugged in to a different slot?
Jorge
2017-07-04 19:07:23 UTC
Permalink
Raw Message
Post by David Schmenk
Post by Jorge
Why is it that the Videx original only works in slot 3 but all the chinesium clones work in any slot? *Cn00L with the Videx gives garbage (but always the same garbage as if it was reading the wrong page into the ROM) for anything but slot n=3. I've got several videx and all of them do the same... Grrr !
Any ideas?
Thanks,
--
Jorge.
Regardless wether the ROM was meant to work in slot 3 or not (I don't recall seeing any slot 3 specific code in the Video ROM), you should still be able to list it in the slot specific ROM address - assuming the qualify the ROM access with /IO-SELECT (can't imagine why they wouldn't). Do you still see the ROM at $C300 even when it's plugged in to a different slot?
I have not checked that, but will do asap and let you know. But I guess the answer is going to be no...

The Videx cards have a bunch of "jumpers" without pins, those of the kind that you have to cut the copper and/or bridge by soldering, I wonder if they may have something to do with this.
Jorge
2017-07-06 21:12:09 UTC
Permalink
Raw Message
Post by David Schmenk
Regardless wether the ROM was meant to work in slot 3 or not (I don't recall seeing any slot 3 specific code in the Video ROM), you should still be able to list it in the slot specific ROM address - assuming the qualify the ROM access with /IO-SELECT (can't imagine why they wouldn't). Do you still see the ROM at $C300 even when it's plugged in to a different slot?
Now I've checked that:

The Cnxx ROM is only visible in the slot the card is plugged in, as it should be, and the C800..CFFF ROM is enabled properly after an access to Cnxx.

Anf the funny things I've discovered so far are:

1.- If the card (and I've got several Videx and all of them do the same) is plugged in an even numbered slot (2,4 or 6) the code I see @ Cn00L is the wrong page. (The previous page of what it ought to be it seems).

2.- In slots 1,3,5 and 7, the code I see @ Cn00L is ok, BUT, the card only works in slot 3, e.g., if I do a C100G or a 1 ctrl-P or a PR#1 it doesn't work and hangs the a2 and I have to reset to recover.

3.- The Videoterm Reference manual says clearly that you can plug it in any slot, but it also says clearly a few pages later that you must plug it in slot 3... Wahaha.

I have several apple IIs, IIes and platinums and all the Videx in all of them behave the same so it's not the apple II.

Also, the ROM in the Videx is a 2708 (unlike the chinese which have 2716s) and that needs (or so it seems) +12v at some pin which I don't remember now, so... if you swap it and put a 2716... you fry it. Whahaha, great!

Any ideas?
Thanks,
--
Jorge.
David Schmenk
2017-07-06 22:22:50 UTC
Permalink
Raw Message
Post by Jorge
Post by David Schmenk
Regardless wether the ROM was meant to work in slot 3 or not (I don't recall seeing any slot 3 specific code in the Video ROM), you should still be able to list it in the slot specific ROM address - assuming the qualify the ROM access with /IO-SELECT (can't imagine why they wouldn't). Do you still see the ROM at $C300 even when it's plugged in to a different slot?
The Cnxx ROM is only visible in the slot the card is plugged in, as it should be, and the C800..CFFF ROM is enabled properly after an access to Cnxx.
3.- The Videoterm Reference manual says clearly that you can plug it in any slot, but it also says clearly a few pages later that you must plug it in slot 3... Wahaha.
I have several apple IIs, IIes and platinums and all the Videx in all of them behave the same so it's not the apple II.
Also, the ROM in the Videx is a 2708 (unlike the chinese which have 2716s) and that needs (or so it seems) +12v at some pin which I don't remember now, so... if you swap it and put a 2716... you fry it. Whahaha, great!
Any ideas?
Thanks,
--
Jorge.
Well, this got my curious. I admit I've never had my Videx in any slot other than 3. So I pulled out my bench ][+ and Videoterm with ROM v 2.3 and plugged it in. Slot 3 worked like a champ. And none of the other slots worked. It acted like it did something, but no video or keyboard response. I was able to see the per-slot ROM in each slot as I would have expected, but it just wouldn't work.

The manual said any slot should be functional, but slot 3 would only work with Pascal and CP/M, as expected. Maybe the earlier ROMs worked in any slot, but not 2.3?
Jorge
2017-07-06 23:59:09 UTC
Permalink
Raw Message
Post by David Schmenk
Well, this got my curious. I admit I've never had my Videx in any slot other than 3. So I pulled out my bench ][+ and Videoterm with ROM v 2.3 and plugged it in. Slot 3 worked like a champ. And none of the other slots worked. It acted like it did something, but no video or keyboard response. I was able to see the per-slot ROM in each slot as I would have expected, but it just wouldn't work.
The manual said any slot should be functional, but slot 3 would only work with Pascal and CP/M, as expected. Maybe the earlier ROMs worked in any slot, but not 2.3?
But, do you see the same code in Cnxx in even and odd slots? I don't, in odd numbered slots a Cn00L begins with a BIT something but in even slots shows something else entirely... ?
David Schmenk
2017-07-07 14:49:11 UTC
Permalink
Raw Message
Post by Jorge
Post by David Schmenk
Well, this got my curious. I admit I've never had my Videx in any slot other than 3. So I pulled out my bench ][+ and Videoterm with ROM v 2.3 and plugged it in. Slot 3 worked like a champ. And none of the other slots worked. It acted like it did something, but no video or keyboard response. I was able to see the per-slot ROM in each slot as I would have expected, but it just wouldn't work.
The manual said any slot should be functional, but slot 3 would only work with Pascal and CP/M, as expected. Maybe the earlier ROMs worked in any slot, but not 2.3?
But, do you see the same code in Cnxx in even and odd slots? I don't, in odd numbered slots a Cn00L begins with a BIT something but in even slots shows something else entirely... ?
I'm away over the weekend so I'll check when I get back. It looked like similar code in each slot, but I'll verify.
Patrick Schaefer
2017-07-07 17:38:58 UTC
Permalink
Raw Message
Post by Jorge
1.- If the card (and I've got several Videx and all of them do the
same) is plugged in an even numbered slot (2,4 or 6) the code I
to be it seems).
Have a look at the Videoterm schematic. Address lines A0..A8 are
connected directly to the EPROM. A0..A7 is what makes the "00" of $Cn00.
And A8 -- oops -- is the lowest part of the "n". Whenever A8 is low
during the /IOSEL access (which is the case for the even-numbered
slots), you will get the wrong page.

To fix this, A8 would have to be ORed with /(/IOSEL). Similar to that
printer card: http://john.ccac.rwth-aachen.de:8000/patrick/data/Printer.pdf
Post by Jorge
3.- The Videoterm Reference manual says clearly that you can plug it
in any slot, but it also says clearly a few pages later that you must
plug it in slot 3... Wahaha.
And you can get it in any color, as long as it is green ;-)


Patrick
Ralf Kiefer
2017-07-07 21:34:16 UTC
Permalink
Raw Message
Post by Patrick Schaefer
To fix this, A8 would have to be ORed with /(/IOSEL). Similar to that
printer card: http://john.ccac.rwth-aachen.de:8000/patrick/data/Printer.pdf
Jorge, do you mean the card you asked for the missing chips two weeks
ago? You added at one position a 74LS02. Probably you should think about
that .....

- Ralf
Jorge
2017-07-13 01:44:01 UTC
Permalink
Raw Message
Post by Ralf Kiefer
Jorge, do you mean the card you asked for the missing chips two weeks
ago? You added at one position a 74LS02. Probably you should think about
that .....
Hi Ralf !

That one is working fine... in any slot :-) only the genuine Videx-es fail. Here's the thing:

In the beginning... all the Videx-es worked fine in any slot, that much I know for sure because I had one that I've lost and I checked that one in other slots many years ago. Even the original 1980 Videx reference manual first edition says:

Page 2-3: "[...] The Videoterm board may go into any of the other slots [...]"

Then, later, in the fourth edition (1982) reference manual, on page "IX" says:

"IMPORTANT NOTICE: THE VIDEOTERM MUST NOW BE PLACED ONLY IN SLOT 3" and more:

http://imgur.com/a/IoVVd

So I think I need to find an old EPROM if I want to use them in other slots, or make one because the complete ROM listings come in the reference manuals.
--
Jorge.
Patrick Schaefer
2017-07-13 20:12:39 UTC
Permalink
Raw Message
Post by Jorge
So I think I need to find an old EPROM if I want to use them in other
slots, or make one because the complete ROM listings come in the
reference manuals.
If you want to be independent of the level at addess line A8, you'll
need an EPROM with the same data in the pages $2xx and $3xx.

As explained before, Videx connected A8 directly to the EPROM, which
means /IOSEL selects EPROM page $3xx for Slot 1, 3, 5, 7 and page $2xx
for Slot 2, 4, 6.


Patrick
Jorge
2017-07-13 21:49:42 UTC
Permalink
Raw Message
Post by Patrick Schaefer
Post by Jorge
So I think I need to find an old EPROM if I want to use them in other
slots, or make one because the complete ROM listings come in the
reference manuals.
If you want to be independent of the level at addess line A8, you'll
need an EPROM with the same data in the pages $2xx and $3xx.
As explained before, Videx connected A8 directly to the EPROM, which
means /IOSEL selects EPROM page $3xx for Slot 1, 3, 5, 7 and page $2xx
for Slot 2, 4, 6.
Patrick
Yes, yes, I know, looking at the ROM listing in the first edition of the reference manual there are two entry points in two succesive pages. I'll just have to copy that listing by hand into another EPROM, I think.

Thanks,
--
Jorge.
Patrick Schaefer
2017-07-13 22:55:47 UTC
Permalink
Raw Message
Post by Jorge
Yes, yes, I know, looking at the ROM listing in the first edition of
the reference manual there are two entry points in two succesive
pages. I'll just have to copy that listing by hand into another EPROM,
I think.
2708 are not very common today. You can use a 2716 instead, if you bend
pin 19 and 21 outside the socket. Pin 21 (Vpp) of the chip should to be
connected to Pin 24 (Vcc), Pin 19 (A10) to Pin 12 (Gnd).

Leaving both pins unconnected might also work if you burn the data two
times, starting at $000 and at $400 (so that A10 is don't care).


Patrick
Jorge
2017-07-15 06:59:19 UTC
Permalink
Raw Message
Post by Patrick Schaefer
Post by Jorge
Yes, yes, I know, looking at the ROM listing in the first edition of
the reference manual there are two entry points in two succesive
pages. I'll just have to copy that listing by hand into another EPROM,
I think.
2708 are not very common today. You can use a 2716 instead, if you bend
pin 19 and 21 outside the socket. Pin 21 (Vpp) of the chip should to be
connected to Pin 24 (Vcc), Pin 19 (A10) to Pin 12 (Gnd).
Leaving both pins unconnected might also work if you burn the data two
times, starting at $000 and at $400 (so that A10 is don't care).
Yes, I've done something like that in the past a few times to replace F8 ROMs with 2716s. Will keep an extra eye on the 2708 +12v pin this time to make sure I don't fry any more 2716s...

The Videoterm maps half the IOStrobe c800.cfff space to ROM and half to RAM, IIRC.

Thanks!
--
Jorge.
James Davis
2017-07-14 00:30:55 UTC
Permalink
Raw Message
Hi Jorge,

I have a Videx-UltraTerm REV.C CARD for sale as is, if you are interested: https://groups.google.com/forum/#!topic/comp.sys.apple2.marketplace/sj2KiKimgOs

James Davis
David Schmenk
2017-07-14 01:10:04 UTC
Permalink
Raw Message
Post by James Davis
Hi Jorge,
I have a Videx-UltraTerm REV.C CARD for sale as is, if you are interested: https://groups.google.com/forum/#!topic/comp.sys.apple2.marketplace/sj2KiKimgOs
James Davis
^^^^^^^^^^^^^^^^^^^^^^^
That's the one you want!
Jorge
2017-07-15 06:29:59 UTC
Permalink
Raw Message
Post by David Schmenk
Post by James Davis
I have a Videx-UltraTerm REV.C CARD for sale
^^^^^^^^^^^^^^^^^^^^^^^
That's the one you want!
It seems that card needs a monitor with long persistance phophor (P39?) because in order to generate the high resolution modes it uses the interlaced mode of the 6845 in which scan lines are only updated at half the normal update rate.

I can do that too with any Videx or clone with a couple of POKEs, BTW, but the flicker you get is annoying.
Ralf Kiefer
2017-07-15 10:56:22 UTC
Permalink
Raw Message
Post by Jorge
It seems that card needs a monitor with long persistance phophor (P39?)
because in order to generate the high resolution modes it uses the
interlaced mode of the 6845 in which scan lines are only updated at half
the normal update rate.
The Apple /// monitor.

- Ralf
Tom Porter
2017-07-15 17:42:22 UTC
Permalink
Raw Message
I was almost finished with a VID-X driver so those people could make or create specific VIDEX games like PONG or whatever... the guy from Brazil I was working with finally got a IIE and didn't need such a driver, so the work stopped. If memory serves me right, we got PLOT and the X,Y down pat, and was just about finished with SCRN but didn't finish... If someone wants to work with me (just test code)... we could finish it and them make a few games for it...
Tom Porter
2017-07-15 17:42:51 UTC
Permalink
Raw Message
We've got a new file called VIDTERM.INF!

This is your new video driver.

It currently has PLOT/UNPLOT & HLIN ON/HLIN OFF
and VLIN ON/OFF.

To use in basic, it replaces the following commands as stated:

PLOTS
OLD: COLOR=1:PLOT X,Y
NEW: CALL 30000,X,Y
---
OLD: COLOR=0:PLOT X,Y
NEW: CALL 30020,X,Y

HLIN
OLD: COLOR=1:HLIN X1,X2 AT Y
NEW: CALL 30050,X1,X2,Y
---
OLD: COLOR=0:HLIN X1,X2 AT Y
NEW: CALL 30075,X1,X2,Y

VLIN
OLD: COLOR=1:VLIN Y1,Y2 AT X
NEW: CALL 30250,Y1,Y2,X
---
OLD: COLOR=0:VLIN Y1,Y2 AT X
NEW: CALL 30275,Y1,Y2,X

EXPLAINED ENTRY....

TO MAKE A VLIN AT 3,25 AT 8 JUST ENTER [ CALL 30250,3,25,8 ]
EVERYTHING HAS A COMMA BETWEEN IT...
PLOTS MUST HAVE 2 DATA PEICES
HLIN/VLIN MUST HAVE 3 DATA PEICES


I debugged it and went thru the code manually, should work fine, I hope?!?
There is no error checking, so if you enter a invalid parameter (out of screen bounds)
it will glitch on you, and do unpredictable things....

IF THE NEW PROGRAM.... [ CURSER2 ] works without glitches then the library is a-ok!
Tom Porter
2017-07-15 17:49:06 UTC
Permalink
Raw Message
According to my notes... the above works... I don't have a VIDTERM so I cant 'test it today'... here is a copy of the driver/work I did on it.. I believe I was pretty close to having an SCRN, but its been a while.

https://www.dropbox.com/s/16ksx3li58l3aw6/Ricardo%205.40l.dsk?dl=0
Jorge
2017-07-14 08:08:43 UTC
Permalink
Raw Message
Post by James Davis
Hi Jorge,
I have a Videx-UltraTerm REV.C CARD for sale as is, if you are interested: https://groups.google.com/forum/#!topic/comp.sys.apple2.marketplace/sj2KiKimgOs
James Davis
I'd love to have one of these beautys, yes, of course! PM me at jorge at jorgechamorro dot com please.

I have always wanted to cannibalize one of these wide screen things:

http://www.ebay.com/itm/282491035184

To use it with a Videx... hahaha, how cool is that? Even more reason yet to want to do that with an Ultraterm.

Magnavox and Brother word processors, and the hp 87 and 2764a, all have those cool wide format CRTs.
--
Jorge.
James Davis
2017-07-14 18:13:26 UTC
Permalink
Raw Message
Post by Jorge
Post by James Davis
Hi Jorge,
I have a Videx-UltraTerm REV.C CARD for sale as is, if you are interested: https://groups.google.com/forum/#!topic/comp.sys.apple2.marketplace/sj2KiKimgOs
James Davis
I'd love to have one of these beautys, yes, of course! PM me at jorge at jorgechamorro dot com please.
http://www.ebay.com/itm/282491035184
To use it with a Videx... hahaha, how cool is that? Even more reason yet to want to do that with an Ultraterm.
Magnavox and Brother word processors, and the hp 87 and 2764a, all have those cool wide format CRTs.
--
Jorge.
OK Jorge,

So, if you are really interested and not broke, go to this link <https://groups.google.com/forum/#!topic/comp.sys.apple2.marketplace/sj2KiKimgOs>, read what it says about placing a bid on the Videx-UltraTerm REV.C CARD I have for sale, and email your bid to me via the 'reply privately' link there.

James Davis
Jorge
2017-07-15 06:31:15 UTC
Permalink
Raw Message
Post by James Davis
Post by Jorge
Post by James Davis
Hi Jorge,
I have a Videx-UltraTerm REV.C CARD for sale as is, if you are interested: https://groups.google.com/forum/#!topic/comp.sys.apple2.marketplace/sj2KiKimgOs
James Davis
I'd love to have one of these beautys, yes, of course! PM me at jorge at jorgechamorro dot com please.
http://www.ebay.com/itm/282491035184
To use it with a Videx... hahaha, how cool is that? Even more reason yet to want to do that with an Ultraterm.
Magnavox and Brother word processors, and the hp 87 and 2764a, all have those cool wide format CRTs.
--
Jorge.
OK Jorge,
So, if you are really interested and not broke, go to this link <https://groups.google.com/forum/#!topic/comp.sys.apple2.marketplace/sj2KiKimgOs>, read what it says about placing a bid on the Videx-UltraTerm REV.C CARD I have for sale, and email your bid to me via the 'reply privately' link there.
James Davis
It seems I'll need to buy a long persistance monitor before... :-/
--
Jorge.
Loading...