• Please review our updated Terms and Rules here

Rainbow 100 Graphic card

na103

Member
Joined
Jun 18, 2020
Messages
41
Location
Campagnola Emilia Italy
Hi,:giggle: I'm trying to remake the Rainbow 100 graphic card, just for fun, using Tony Duell's schematics.
can anyone take some high resolution pictures of this card (front and rear) and or original schematics ?
help would be greatly appreciated
Regards
Nicola
DEC_5015687_RainbowGraphicsCard.jpg
 

N. Brown

Experienced Member
Joined
Mar 3, 2022
Messages
55
I see that your post is a couple of years old, so how is it going.
The price I got for this card was $500.xx Canadian a couple of years ago. I could use 3 of them if they where affordable.
The schematics at bitsavers.org are pretty good but their not for the 3Rd parity enhanced version.
 

na103

Member
Joined
Jun 18, 2020
Messages
41
Location
Campagnola Emilia Italy
I see that your post is a couple of years old, so how is it going.
The price I got for this card was $500.xx Canadian a couple of years ago. I could use 3 of them if they where affordable.
The schematics at bitsavers.org are pretty good but their not for the 3Rd parity enhanced version.
I haven't done anything yet, I'm waiting first to collect pictures, schemes and information.
based on this I will decide whether to try this challenge
i didn't know of a third party enhanced version, do you have any more information to give me?
 

N. Brown

Experienced Member
Joined
Mar 3, 2022
Messages
55
Sorry bad date, split screens open and I was in a rush with a hard to read screen (sun on it), bad auto correct, cheap keyboard. Ops - sorry about that.
Other 3Rd party board that are based on the NEC 7220 are mostly the same as above. But they use extra register bits for more memory selection since the chip supports 256K by 16 bits. Some would take up to 1 Meg of memory, 4 banks of 256K. Mostly to add DEC Pro series and other resolutions.
..
On the Dec rainbow 100 that I use to refurbish for resale, I used a different card that added basically IBM EGA, PGA emulation to it. ( Basically it was cheaper to make then dec's version). But the drivers for this card are now owned by others. Schematics are in storage. But you should still be able to find the register information online for IBM compatible displays if you decide to go that way. The warning about this is that if the IBM PC BIOS emulator is loaded, any address call translations by it the card must see it.
..
It is also possible to build a graphics overlay card, that user the rainbows on board video controller chips DC11 and JC12 to do color graphics. but this requires desording IC's and adding several sockets
..
As far as color pictures, any I would have would be about the same quality as the old ones already on the internet.
..
For extended color selection on the RB100A models you must add resistors that already included on the rb100B, I think they where R32 a 715 @1% tolerance and R33 249 @ 1% tolerance. I would have to dig out a RB100A Schematic diagram to verify this. Resistors for Vid 3H and Vid 4H where not install on the RB100A ? I think.
For some odd unknown reason the authors of how to convert a RB100A to RB100B skip it, Missed it (Maybe the did not have the schematics for the RB100A).

Unfortunately the included scan is clip off by the systems external I/O ports - So I don't know if it would help you any.
(type o) several entering this message, unfixed ?
 

Attachments

  • RB100_PCBlayout(not+orB).pdf
    58.2 KB · Views: 9

N. Brown

Experienced Member
Joined
Mar 3, 2022
Messages
55
On the Dec. Rainbow 100 model A, the two resistors to add are for resistor locations R125 and R126. They are located on the bottom right hand side by connector J9.
The value for them both are 1M @.25W 5.0% Tol. Note that : R125 is used with GRFVid 3H output pin 6 of ICE1 an 74ls12 and R126 is used with GRFVid 4H output pin 8 of ICE1.
The values in for the model 100B and the 100+ are different, for these you can read the technical manuals available at www.bitsavers.org computer archive section. (Logic is some what different). GRFVid 4H resistor R32 was 348, GRFVid3H resistor R31 was 715, GRFVid2H resistor R30 was 1.4K, GRFVid1H resistor R29 was 2.8K.
....... Some other values where also used depending on country location outside of North American and the type of monitor connected to it. (AKA. 128 Color/Gray scale units)
Hopefully no type o's - sorry cant append to above message. (supported ?)
 

na103

Member
Joined
Jun 18, 2020
Messages
41
Location
Campagnola Emilia Italy
Hi,:giggle: I'm trying to remake the Rainbow 100 graphic card, just for fun, using Tony Duell's schematics.
can anyone take some high resolution pictures of this card (front and rear) and or original schematics ?
help would be greatly appreciated
Regards
Nicola
hi fans of the Rainbow 100, an update for you on my graphics board rebuild work.
I completed the design of the diagrams with kicad and I verified them by tracing the routing on the images of the board.

there is a lot to do but I hope for Christmas to be able to produce it.

screenshot.PNG

layer.png
 

N. Brown

Experienced Member
Joined
Mar 3, 2022
Messages
55
In a past message I did originally comment about it with the wrong year dated. But anyway it is cool if you plan to do a small production run on them.
Depending on their cost, I could also use a couple of them.
In your design are you planning to updating the video memory to 256K sized memory chips and patch a driver for it.
The old NEC UPD7020 supports up to A17 (Address line) so 256K of memory is possible.
..
AS you are probably aware the programming manual is available @ http://www.bitsavers.org/pdf/dec/rainbow/
AA-AE36A-TV_Rainbow_Color_Graphics_Option_Programmers_Reference_Guide_Jun84.pdf
..
With newer written drivers other resolutions should also be possible since the Dec. RB100 can do a 132 column by 66 line text display with its onboard
video controller chips. In theory it should be possible to add a emulation of the IBM PC's EGA card color registers but the control register U would use a MCU to emulate them.
Have the MCU translate the EGA cards control registers in to 7220 controllers format and send it to it.
...
As far as other possible future updates Elektor (electronics) Magazine (UK edition) did :
March-1988 did a A 256-Colour Adapter For The EGA Gard, and some Background data is in April 1986 under the article called "Digital Color Palette" will
offer up to 4096 possible colour palette (12-bit).
..
Hopefully some other reader will upload a high resolution pictures of this card (front and rear). As far as the original schematics from DEC. their where other manufactures card that where similar but their addressing is different that might be easier to get a hold of. The diagrams in the attached manual has the NEC configuration example in it. The register data in this issue is not the greatest. The old 7220 graphics controller project for the APPLE II bus might me another great one to check out for their design ideals in order to get it to work with the Apple II computer. (Links included down below)
..
The old IBM PC ISA bus compatible 7220 graphics controller might me another great one to check out but I forget the date and what magazine it was in and who made it. ??
..
The 7220 graphics controller project for the Apple II is in the archive at ARCHIVE.ORG see:
Radio-Electronics Magazine Feb. 1986 issue has the Build the GRAFEX-32 Part 1 in the ComputerDigest section. I think it started on page 103 ? bit I don't remember for sure.
Radio-Electronics Magazine March 1986 issue has the Build the GRAFEX-32 Part 2 in the ComputerDigest section.
Radio-Electronics Magazine April 1986 issue has the Build the GRAFEX-32 Part 3 in the ComputerDigest section.
EleKtor Magazine UK addition is available @ https://worldradiohistory.com/Elektor.htm
EleKtor (electronics) Magazine March-1988 did a A 256-Colour Adapter For The Ega (UK/IR addition)
Background data is in April 1986 issue under the article called "Digital Color Palette" will offer upto 4096 possible colour palette (12-bit)
..
Our host stated that the complete magazine issues to be uploaded is too big - so I will just include the likes for now. (The Uploaded file is too large.)
If the additional data links provided is of no future help - then just forget about them.
..
Thanks' for reading.
 

Attachments

  • uPD7220-uPD7220A_User_Manual_Dec85.pdf
    3.5 MB · Views: 2

na103

Member
Joined
Jun 18, 2020
Messages
41
Location
Campagnola Emilia Italy
Hi N. Brown,
Thanks for all these suggestions regarding possible board upgrade.

for the moment I am working on the reconstruction of the original pcb including the bodge wire.
When it is finished I will not sell anything but as I did with the memory expansion
I will share all the necessary information to those who want to build it.

However, the number of ICs on the board and the rarity of some of them suggest to me that it won't be cheap to produce.
It would probably be cheaper to create an improved FPGA version, more memory and EGA emulation, but this is beyond my skills and knowledge.
in any case I will take some time to study the changes you propose and I will let you know.

Greetings
Nicola
 

MattisLind

Veteran Member
Joined
Sep 30, 2013
Messages
1,006
Location
Stockholm, Sweden
Hello! Really good work you have done with the mem expansion board and this board.

Not really related to the Rainbow card itself but more on the process to reverse engineer it.

It would be very interesting to hear about how you do it.

Perhaps this is stupid questions. Nevertheless.
The board has at least four layers as it seems. How can you get a good picture of the top layer with components in place?

Do you make a netlist from this picture?

I have a bunch of mostly double sided boards that I would like to reverse engineer into proper netlists. It would be awesome to learn a good method of doing that.
 

na103

Member
Joined
Jun 18, 2020
Messages
41
Location
Campagnola Emilia Italy
Hello! Really good work you have done with the mem expansion board and this board.

Not really related to the Rainbow card itself but more on the process to reverse engineer it.

It would be very interesting to hear about how you do it.

Perhaps this is stupid questions. Nevertheless.
The board has at least four layers as it seems. How can you get a good picture of the top layer with components in place?

Do you make a netlist from this picture?

I have a bunch of mostly double sided boards that I would like to reverse engineer into proper netlists. It would be awesome to learn a good method of doing that.
Hi,
take a look these two videos where master Eric Schlaepfer explains how to approach reverse engineering, I followed the same procedure

 

na103

Member
Joined
Jun 18, 2020
Messages
41
Location
Campagnola Emilia Italy
I am sorry to tell you that I will not build this board because the cost, over $400, is too high for my limited budget.
however I share all my work in case someone in the future can try to build or just use it for restore/fix the original board.
below the list of all components, the gerber for the pcb like original board and my new version with some corrections, I removed bodge wire and replaces the DIP array resistor with more common SIP.
the files needed to program the GAL and PROMs are also attached

front.PNG
back.PNG


TypePositionMouser or Digikey Parts
3​
74LS112U1 U5 U49SN74LS112AN
2​
74LS174U2 U91SN74LS174N
3​
74F374U3 U30 U58SN74F374N
5​
74LS74U4 U6 U7 U38 U64SN74LS74AN
4​
74LS597U8 U16 U17 U25SN74LS597N ebay
2​
74F174U9 U59SN74F174AN
4​
74F74U13 U39 U45 U94SN74F74N
2​
74LS00U14 U23SN74LS00N
3​
74LS08U15 U42 U51SN74LS08N
6​
74LS163U18 U26 U32 U40 U44 U52SN74LS163AN
1​
74LS368U22SN74LS368AN
3​
74LS04U24 U33 U48SN74LS04N
3​
74LS02U41 U56 U66SN74LS02N
1​
74LS139U43SN74LS139AN
3​
74F157U46 U54 U62SN74F157AN
6​
74LS32U47 U53 U55 U65 U71 U88SN74LS32N
1​
74LS138U50SN74LS138N
4​
74LS245U60 U75 U96 U99SN74LS245N
6​
74F373U63 U73 U74 U76 U79 U100SN74F373N
3​
74LS393U68 U72 U77SN74LS393N
4​
74LS157U69 U78 U97 U98SN74LS157N
2​
74LS373U70 U86SN74LS373N
2​
74LS153U80 U87SN74LS153N
1​
74LS169U81SN74LS169BN
1​
74LS30U83SN74LS30N
1​
74LS75U93SN74LS75N
1​
74LS165U102SN74LS165AN
2​
GAL16V8U90 U95ATF16V8BQL-15PU
1​
Oscillator 31.188MhzU31ECS-P145-AX
2​
15 4.7k resistor array DIPU57 U824116R-2-472LF
1​
15 560 resistor array DIPU674116R-2-561LF
8​
DRAM 4164-15U10 U11 U19 U20 U28 U29 U36 U37Ebay
2​
PROM 74S472U12 U21Ebay DM74S472AN
6​
SRAM 74S189U27 U34 U35 U61 U92 U101Ebay
1​
NEC D7220D-1U84Ebay
1​
SRAM 16k (2k*8)U85Ebay HM6116P-2 or AM9128-10
4​
715R 1/4W 1%R1 R3 R4 R16MF1/4DC7150F
1​
4.7K 1/4W 1%R2MF1/4CCT52R4701F
3​
2.8K 1/4W 1%R5 R11 R18MF1/4DC2801F
1​
50R 1/4W 1%R6MFR-25FTE52-50R
3​
348R 1/4W 1%R7 R9 R10MF1/4CC3480F
3​
75R 1/4W 1%R12 R22 R24MFS1/4DCT52R75R0F
1​
249R 1/4W 1%R8MF1/4CC2490F
3​
1.4K 1/4W 1%R13 R15 R17MF1/4DC1401F
3​
121R 1/4W 1%R14 R20 R23MF1/4CC1210F
1​
180R 1/4W 1%R19MF1/4DCT52R1800F
1​
62R 1/4W 1%R21271-62-RC
2​
82R 1/4W 1%R25 R30MF1/4DC82R0F
1​
200R 1/4W 1%R26MF1/4DC2000F
2​
1K 1/4W 1%R27 R28MF1/4DCT26A1001F
1​
51R 2W 1%R29WHC51RFET
3​
4.7K x 7RN1 RN2 RN64608X-AP1-472LF
2​
560R x 7RN3 RN44608X-101-561LF
1​
4.7K x 8RN54609X-101-472LF
42​
47nF 0.047uF 50V axialC1-C3 C6-C8 C11 C12 C15 C16 C19 C20 C23-C25 C30-C49 C52-C58A473K15X7RF5UAAP
8​
220nF 0.22uF 50V axialC4 C5 C9 C10 C13 C14 C21 C22A224K20X7RF5UAAP
7​
10 nF 0.01uF 50V axialC17 C18 C26-C29 C51A103K15X7RF5UAA
1​
4.7 uF 50V axialC50475TTA050M
1​
1N754A VZ= 6.8 1% 400MWD11N754A
1​
1N4619 VZ= 3.0 1% 250MWD21N4619
3​
2N2905AQ1 Q2 Q32N2905A
1​
J140pos 571-7-534206-0 or 48pos 571-2-535542-4
14​
Socket DIP 16U10 U11 U19 U20 U28 U29 U36 U37 U27 U34 U35 U61 U92 U1011-2199298-4
4​
Socket DIP 20U12 U21 U90 U951-2199298-6
1​
Socket DIP 40U841-2199299-5
1​
Socket DIP 24ICA-624-SGT
 

Attachments

  • Gerber_new.zip
    1.7 MB · Views: 1
  • Gerber_original.zip
    1.7 MB · Views: 0
  • U21-U12.zip
    1.2 KB · Views: 1
  • U90-U95.zip
    1.2 KB · Views: 1

Roland Huisman

Veteran Member
Joined
Mar 24, 2011
Messages
1,396
Location
The Netherlands
Some collectors have piles of old TTL chips and might be able to build such a board for not too much money. But when you have to buy all the chips for the full price, things will become a bit different. Sometimes I don't care too much about projects being too expensive... As long as the fun/price ratio is good... I hope someone else will finish your project!
 

VERAULT

Veteran Member
Joined
Jan 30, 2012
Messages
6,284
Location
Connecticut, USA
So you have no built the card up to see if it at least is functional? You could probably make all your money back if you paced yourself on parts. I can do this for far less that $400.00 for sure. PRinting the board would be the most expensive part.
 

na103

Member
Joined
Jun 18, 2020
Messages
41
Location
Campagnola Emilia Italy
Some collectors have piles of old TTL chips and might be able to build such a board for not too much money. But when you have to buy all the chips for the full price, things will become a bit different. Sometimes I don't care too much about projects being too expensive... As long as the fun/price ratio is good... I hope someone else will finish your project!
vintage components, such as the NEC D7220AD-1 7Mhz, are not easy to find, there are many fakes on ebay and it is not easy to test. perhaps with patience I could recover the components from some board and halve the budget.
 

na103

Member
Joined
Jun 18, 2020
Messages
41
Location
Campagnola Emilia Italy
are you offering me a business partnership? :p ;)
if you want to try to build it you have all my support
So you have no built the card up to see if it at least is functional? You could probably make all your money back if you paced yourself on parts. I can do this for far less that $400.00 for sure. PRinting the board would be the most expensive part.
 

Teletech

Experienced Member
Joined
Jul 25, 2022
Messages
194
I am sorry to tell you that I will not build this board because the cost, over $400, is too high for my limited budget.
however I share all my work in case someone in the future can try to build or just use it for restore/fix the original board.

A really impressive effort! I'm not a big Rainbow fan, but the amount of work you put in here is remarkable. Let me know when you replicate a PEP-70 though!
 
  • Like
Reactions: erd
Top