HP48 - InVision48 projector

[hughwong]

l have a InVision48 projector device which suppose to project the screen of the HP48 on to a projector screen. I got this used a long time ago, I could not remember I ever tested it. Now I am retired and wish to test the machine. When I examined the cable came with it, it have two ends, one is a six prong phone jack that plugs into the device, the other is a 8 prong female jack suppose to plug into the calculator. I could not find a HP48 with a 8 pin jack, Does anybody can give me some advise ? Thank You.[/size]

[Raymond Del Tondo]

The InVision48 came with a plug-in card for the HP 48SX. The card may have a suitable cable attached.

HTH

[Joe Horn]

One possibility: If you have this panel, and if the plug for the calculator actually has 10 pins, not 8, then you have the cable for an HP 49G, not an HP 48:

[BruceH]

I don't recognise the name "InVision48".

There was an HP projector for the 48 and 49 - which looks as per the photo in Joe's post above. It came with two cables: one for the 48SX which has a dummy card attached and slides into the card slot, and one for the 49G which goes into the serial port.

Note that the HP projector contains a 9v PPC battery (remove the back cover) which will almost certainly be dead by now.

[Han]

(02-16-2014 10:29 PM)Joe Horn Wrote:  One possibility: If you have this panel, and if the plug for the calculator actually has 10 pins, not 8, then you have the cable for an HP 49G, not an HP 48:

Was there never an back-ward compatible adapter for the HP48? I know they had such adapters for wire transfer. I take it these did not have proper LCD lines.

[BruceH]

(02-17-2014 07:57 PM)Han Wrote:  Was there never an back-ward compatible adapter for the HP48? I know they had such adapters for wire transfer. I take it these did not have proper LCD lines.

Correct. The 48 socket only has four pins - so not enough to carry the display as well as serial data.

[Joe Horn]

(02-17-2014 07:57 PM)Han Wrote:  Was there never an back-ward compatible adapter for the HP48? I know they had such adapters for wire transfer. I take it these did not have proper LCD lines.

As Raymond mentioned, the LCD panel came with a 48 cable, whose calculator end was shaped like a RAM card, which you plugged directly into the card slot. The 48SX used some of the pins in its card slots for display information, which the 48 cable sent to the LCD panel.

IIRC, the 48GX does not have the display info on those pins, so the panel cannot be used with a GX. But I also seem to remember that the GX's card slot #1 has different pin information than slot #2... so maybe the panel can be used in slot #1 of the GX. I do know for sure that it can't be used in a GX's slot #2, which used the former display lines for bank-switching multi-port RAM cards.

[Han]

(02-18-2014 12:16 AM)BruceH Wrote:  

(02-17-2014 07:57 PM)Han Wrote:  Was there never an back-ward compatible adapter for the HP48? I know they had such adapters for wire transfer. I take it these did not have proper LCD lines.

Correct. The 48 socket only has four pins - so not enough to carry the display as well as serial data.

No, that wasn't quite what I was referring to. The serial port is completely separate. The HP48 version had an card interface, and the cable attached to that card. So I was wondering if the cable-to-card interface had an adapter.

[Han]

(02-18-2014 12:57 PM)Joe Horn Wrote:  

(02-17-2014 07:57 PM)Han Wrote:  Was there never an back-ward compatible adapter for the HP48? I know they had such adapters for wire transfer. I take it these did not have proper LCD lines.

As Raymond mentioned, the LCD panel came with a 48 cable, whose calculator end was shaped like a RAM card, which you plugged directly into the card slot. The 48SX used some of the pins in its card slots for display information, which the 48 cable sent to the LCD panel.

IIRC, the 48GX does not have the display info on those pins, so the panel cannot be used with a GX. But I also seem to remember that the GX's card slot #1 has different pin information than slot #2... so maybe the panel can be used in slot #1 of the GX. I do know for sure that it can't be used in a GX's slot #2, which used the former display lines for bank-switching multi-port RAM cards.

Card slot 1 is indeed different. In fact, on the GX, card slot 1 is identical (I think) to the card slots on the HP48SX. Card slot 2 on the GX had the display lines replaced with address lines connected to a multiplexer which handled bank switching. Anyway, the card slot interface for the HP48 version of the overhead display was what prompted my question... alas no one seems to have one on hand, then?

[BruceH]

(02-18-2014 08:13 PM)Han Wrote:  No, that wasn't quite what I was referring to. The serial port is completely separate. The HP48 version had an card interface, and the cable attached to that card. So I was wondering if the cable-to-card interface had an adapter.

The cable is hard-wired into the card in the HP version of the projector. I don't know about the InVision.

[hughwong]

First, I have re-exam the cable, it is a ten pin female, then I got a HP49 and tested it and it worked without any additional power source, it just uses the HP49 power. Attached is some photos I took for everybody. Thanks for the input.

[Raymond Del Tondo]

(02-23-2014 07:50 PM)hughwong Wrote:  First, I have re-exam the cable, it is a ten pin female, then I got a HP49 and tested it and it worked without any additional power source, it just uses the HP49 power. Attached is some photos I took for everybody. Thanks for the input.

Did you forget the attachments?

[hughwong]

Hi,

I am sorry I could not up load the pictures, because I am new to the forum, but if you like to see the item, I had it listed on ebay as the following link:

http://www.ebay.com/itm/201047352657?ssP...1558.l2649


Thanks for responding

[Raymond Del Tondo]

Hi,

thanks for the link:-)
So it's the "older style" version in beige, which came from FSI directly. The other one, pictured by JKH, has an HP logo and number IIRC.
I think I still have one replacement LCD for the older unit;-)

[hughwong]

Hi Ray,

I got this at least 12 years ago. I have used it a few times to engineering students, ever since I never used it. But now I realize this unit need an interface board in order to work with the HP48. Do you have a interface board that works ? If you do may be I can auction it at a higher price and I can share the proceed with you.

hugh wong

[Cricket]

I have a newly acquired overhead display unit that looks just like the one pictured by Joe Horn that came with cables for the 38G and the 48GX. The 48 cable plugs in the card slot and the 38G cable is a female 10 pin and plugs in the 38G. So far I have had success in getting the 38G to work, but have had no success with the 48. This is really why I was hunting info on this subject. The overhead unit I have is said to be a F1212A Overhead Display Unit and it bears the HP name and Logo. One more thing, the end of my cable that plugs to the overhead is a 8 pin circular plug that is similar to a Mouse Cable plug. I hope this helps.
Personally I could use some help locating some documentation on how to operate the projector if it exists. I am going to heed Joe's suggestion and try slot #1 on my GX.

[Raymond Del Tondo]

(03-06-2014 07:55 PM)hughwong Wrote:  Do you have a interface board that works ?

Hi,
And sorry for the late reply...
The only physical InVision48 units I have seen were back when I visited Firmware Systems in Corvallis.
That's where Vern gave me the LCD, and unfortunately the LCD is the only part I have.

Cheers