BIT-C-128
Video DAC for Commodore 128/128D, IBM CGA, and Tandy CGA Plus
What to Buy
I offer accessories to help people get up and running quickly, and to save money on shipping when buying items together. If you aren't sure what all you will need or want and/or would like to try the video DAC in unusual applications, please contact me for assistance before placing your order.
What you need really depends on what you want to do with your computer (Commodore 128, IBM CGA, etc.) and your display (VGA or pre-VGA <17 kHz CRT).
For IBM CGA and/or Commodore 128 in 80-Column Mode on a VGA Display
For the most-common application—using a VGA display with a Commodore 128 in only 80-column mode or IBM CGA—buy:
- the BIT-C-128 Video DAC
- a good 5-volt power adapter (here or elsewhere; note that poor-quality power adapters deliver poor-quality video)
- one of the Gonbes units (GBS-8220 recommended)
The above combination will allow most Commodore 128 users to get started cheaply, while giving the option to add 40-column mode in grayscale by simply adding a cable (as described on the applications page), and to get 40-column mode in color by adding the following:
For Commodore 128 in 40-Column Mode on a VGA Display
To get 40-column mode in color, add to the above with the following:
- Ambery SDV1
- a triple (or 3 single) RCA-style male-male cable(s) – to connect the Ambery and Gonbes units for color 40-column mode
- a Commodore video cable: circular DIN to S-Video (best) or composite RCA-style connector – to connect the Ambery unit to the Commodore 128
(Please note that the Commodore 128 may also be used with a VGA display in color 80-column mode and grayscale-only 40-column mode without the Ambery SDV1 using a Commodore video cable with composite RCA-style connector – to connect the Gonbes unit to the Commodore 128, as described above and on the applications page.)
For Slow-Scan (17 kHz) CRT Displays
Alternately, a pre-VGA (<17 kHz) CRT display may also be used with a Commodore 128 in color 80-column mode or IBM CGA using (as also described on the applications page):
- the BIT-C-128 Video DAC
- a good 5-volt power adapter (bought here or elsewhere)
- a 2-wire power kit – to connect the power adapter to the video DAC
- a video cable to the CRT, such as the multiple-BNC cable listed below
- a 6-wire video signal kit (if using the BNC cable)
Where to Buy
Sales resume in 2024 via the new BIT-C-128 store on Square. Please note that orders placed in January may require up to two weeks to process, which should return to the usual three days thereafter.
To see larger images, click below on the thumbnails or linked text in the item descriptions. Use your browser's "back" button to return to this page.
| Use | Item | Price |
80-
COL |
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BIT-C-128 Video DAC (Digital-to-Analog Converter)
for Commodore 128/128D 80-column output and IBM CGA
Use with external +5 V DC power source and Gonbes GBS-8220 (recommended) or GBS-8200 to connect VGA display, or wire kits to connect pre-VGA (<17 kHz) analog RGB display |
$45.00 (Save!) |
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Triad Magnetics WSU050-2000 Power Adapter
Powers Gonbes GBS-8200 or GBS-8220, and video DAC through Gonbes unit or 2-wire kit
input: 100-240V AC at 50 or 60 Hz (worldwide), North American plug
output: +5 V DC @ 2 A with low ripple, center positive barrel connector
Recommended for use in North America
Not compatible with plug adapters listed below |
$11.50 |
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NEW! International Power Adapter, works with snap-on plug adapters
Powers Gonbes GBS-8200 or GBS-8220, and video DAC through Gonbes unit or 2-wire kit
input: 90-264V AC at 50 or 60 Hz (worldwide), folding North American plug
output: +5 V DC @ 2 A with low ripple, center positive barrel connector
Recommended for use outside North America with snap-on plug adapter(s) below |
$13.25 |
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NEW! Argentina Snap-on Plug Adapter for International Power Adapter
Fits over North American plug
May be used only with International Power Adapter |
$1.75 |
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NEW! Australia/New Zealand Snap-on Plug Adapter for International Power Adapter
Fits over North American plug
May be used only with International Power Adapter |
$1.75 |
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NEW! Brazil Snap-on Plug Adapter for International Power Adapter
Fits over North American plug
May be used only with International Power Adapter |
$1.75 |
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NEW! China Snap-on Plug Adapter for International Power Adapter
Fits over North American plug
May be used only with International Power Adapter |
$1.75 |
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NEW! Europe Snap-on Plug Adapter for International Power Adapter
Fits over North American plug
May be used only with International Power Adapter |
$1.75 |
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NEW! Korea Snap-on Plug Adapter for International Power Adapter
Fits over North American plug
May be used only with International Power Adapter |
$1.75 |
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NEW! United Kingdom Snap-on Plug Adapter for International Power Adapter
Fits over North American plug
May be used only with International Power Adapter |
$1.75 |
| VGA |
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Gonbes GBS-8220 (two VGA outputs)
Converts low-frequency analog CGA from the video DAC to higher-frequency VGA
Includes 2-wire power and 6-wire video cables
(Recommended) |
about $26 incl. shipping;
search for best price with Google shopping |
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Gonbes GBS-8200 (one VGA output)
Converts low-frequency analog CGA from the video DAC to higher-frequency VGA
Includes 2-wire power and 6-wire video cables |
about $16 incl. shipping from GearBest
(slow delivery, >2 weeks) |
40-
COL |
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Ambery SDV1 Composite/S-Video to Component Video/RGB Sync-On-Green Converter
Add color in 40-column modes |
$80 from Ambery |
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DE-9 Extension Cable
2 m (6.5') long, with molded connectors and tool-free screws
Allows the video DAC to be used at the end of the cable (optional jack screws recommended) |
$5.00 |
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Pair of Hexagonal Jack Screws
3/16" (4.7625 mm) long
Recommended to fasten the extention cable to the video DAC
Allows mounting the video DAC through panels with thickness of up to about 1/16" (1.5875 mm) |
$0.75 |
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for BIT-C-128 Video DAC only:
"Commodore 128 128D 128DCR C-128 RGBi DAC case for Bit-c128 DAC device - NEW"
3-D printed case available in choice of colors |
$9.99 via eBay
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for Gonbes GBS-8200 only:
"Case for GBS8200 - WHITE (single VGA output)"
3-D printed white case |
$19.99 via eBay
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for Gonbes GBS-8220 only:
"Case for GBS8220 - WHITE (dual VGA output)"
3-D printed white case |
$19.99 via eBay
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for Gonbes GBS-8200 only:
"PREMIUM QUALITY Case for GBS8200 - Cobalt Translucent Blue (single VGA output)"
3-D printed blue case |
$29.99 via eBay
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for Gonbes GBS-8200 only:
"PREMIUM QUALITY Case for GBS8200 - Bright Orange (single VGA output)"
3-D printed orange case |
$29.99 via eBay
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for Gonbes GBS-8200 and a video DAC (select BIT-C-128 Video DAC):
"THE ORIGINAL - Made in USA, Commodore 128 VGA Module - case only"
3-D printed white Commodore-style case |
$24.99 via eBay
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for Gonbes GBS-8200 and BIT-C-128 Video DAC:
"PREMIUM QUALITY Commodore 128 Dual VGA Module (BIT-C-128 Video DAC+GBS8200) Case"
3-D printed blue case |
$39.99 via eBay
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VGA-to-BNC Cable
black, 2 m (6.5') long, with molded connectors and tool-free screws
Connect pre-VGA (<17 kHz) analog RGB monitors with BNC inputs to the 6-wire connector kit |
$20.00 |
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6-Wire Signal Kit for VGA-to-BNC Cable
VGA-style 15-pin D-sub connector with hood and 6 wires with tinned ends
For use with VGA-to-BNC cable and pre-VGA (< kHzlt;< kHznbsp;kHz) monitors (optional hex nuts recommended) |
$7.50 |
 |
2-Wire Power Kit for AC Adapter
Barrel connector to two wires with tinned ends
If not using a Gonbes unit, this allows the power adapter to plug neatly into the video DAC |
$5.00 |
 |
Pair of Hexagonal Nuts
1/4" (6.35 mm) long
Fastens two D-sub connectors inline together
Recommended to fasten the VGA-to-BNC cable to the 6-wire kit |
$0.75 |
Sales Tax
Sales tax will be added automatically as applicable.
Shipping and Handling
Orders ship via the United States Postal Service (USPS), which delivers to most of the world. (March 2022 update: Delivery to Russia and selected Russian allies are now suspended due to its ongoing attack of Ukraine.)
I ship nearly all orders out within 2 business days. Delivery within the United States takes usually about another 3 days, and to the rest of the world could take 1-4 weeks. (I'm looking into speedier options.)
Shipping and handling charges are calculated automatically and based on destination. Economy shipping is also based on weight, and most orders ship as highlighted below.
USA Domestic Economy
(First Class Mail) |
|---|
Weight
(pounds) | Rate
(USD) |
|---|
| 0.00-0.06 lb | $1.00 |
| 0.07-0.15 lb | $8.00 |
| 0.16-0.88 lb | $10.00 |
| 0.89-1.00 lb | $14.00 |
|
| International Shipping Rates (USD) |
|---|
Weight
(pounds) | Destination |
|---|
| Canada | Mexico | others |
|---|
| 0.00-0.50 lbs | $18.00 | $22.00 | $25.00 |
| 0.51-2.00 lbs | $18.00 | $22.00 | $25.00 |
| 2.01-3.00 lbs | $27.00 | $32.00 | $35.00 |
| 3.01-4.00 lbs | $37.00 | $43.00 | $50.00 |
|
Shipping via USPS Priority Mail is now available to USA destinations, and should be selected for orders weighing more than one pound.
If you wish to place an international order weighing more than four pounds, please inquire using the contact page.
Warranty
I warrant everything I sell to be free from material defects in components and workmanship for at least one year, and will repair or replace (at my discretion) any defective product including shipping costs, provided that the video DAC is powered with nominally 5 volts as specified.
If you accidentally break something and it wasn't due to a defect, please contact me and I will do what I can to fix it.
Satifaction Guarantee
If you are unhappy with any product for any reason other than a defect within 90 days (or longer, at my discretion), simply pay return shipping and receive a full refund. (In the United States, please use insured first class mail.)
Questions?
If you have any questions or comments, or would like help ordering or chosing the right accessories for your application, please contact me.
