==Manuals and Documentation==
===Where are the manuals?===
:Except for the differences listed in [[Overview]], the SBC6120-RC is functionally identical to the SBC6120. The -RC uses the same firmware, has the same ROM monitor commands, runs OS/8 and uses the same OS/8 device drivers, and has the same switches and lights on the front panel. For more information about the SBC6120-Rc you should read the SBC6120 manuals, 
::http://www.sparetimegizmos.com/Downloads/SBC6120.pdf 
::http://www.sparetimegizmos.com/Downloads/FP6120.pdf

==Disks and Mass Storage==
===No disk drive? Do you want me to toggle in my programs everytime ??===
:There's a non-volatile, battery backed up, RAM disk built into the SBC6120-RC. It's software compatible with the RAM disk option for the original SBC6120 and can store up to 1MW (that's 1 million 12 bit words).

===Only 1MW for the RAMdisk? That's not enough!===
:Trust me, it's plenty. 1MW is 4096 OS/8 disk blocks, which is as big as any single OS?8 device can be. OS/8 would happily run on a dual RX01 floppy disk system, and the SBC6120-RC RAMdisk is as big as eight floppy diskettes.

===How do I load a disk image into the RAMdisk?===
:By downloading the disk image over the serial port, using the same BTS6120 ROM monitor image download functions as the original SBC6120. See this FAQ, "Where are the manuals?"

===Download over the serial port? That'll take forever!===
:It takes a couple of hours, but you only have to do it once. Start it up, go out and have dinner, and it'll be done when you get back.

===Can I plug an ATA/IDE disk into J5?? It has the right number of pins...===
:Absolutely not! The SBC6120-RC has no IDE/ATA port and J5 is most certainly not wired for one. If you try to plug a disk or CF card into J5, it'll never work and you'll probably fry something. If you want to know more, see the next question.

===Why does my 512kW SBC6120-RC says "448K memory" when it boots?===
:BTS6120 is reporting the size of the RAM disk, not the total memory. The HD6120 always reserves 32kW for main memory and 32kW for CP memory, so 512kW minus 64kW gives 448kW and 1MW minus 64kW is 960kW.

==Terminals and Serial Ports==
===I get output on my terminal but the input doesn't work...===
:If you aren't using the VT6, be sure you installed the jumper at D2 as directed in the assembly instructions. If you are using the VT6, be sure you installed the additional parts, especially D2, D3 and R6.

===If I have the VT6, can I use the DB9/KL8E port for something else?===
:No. The VT6 uses the same KL8 console port as any other terminal would - the VT6 just bolts onto the SBC6120-RC motherboard. You can, however, still attach the DB9 port to a PC and use it to download disk images even if you are using the VT6, but that's a special case. Except for that, if you're using the VT6 you can't use the DB9 serial port.

==Construction and Parts==
===Some parts seem to be missing from my PCB!===
:R3, R4, R5 and J5 are never used and should not be installed. J2, J4, R6, D2 and D3 are used only if the VT6 is also installed. U10 and U11 and the associated bypass capacitors are used only when the memory is expanded to 1MW. The SBC6120-RC can easily run OS/8 (DEC's disk operating system for the PDP-8) using the same RAM disk device driver as the SBC6120.

===What's J5 for??===
:The original purpose was to make it easy for me to plug in a Logic Analyzer while I was debugging the initial design. You could always use it for the same if you had a problem to debug. Many people will ask "Couldn't it be used for an expansion board?" - the answer is "possibly". Most or all of the necessary interface signals are there and a clever person could probably work something out, but at the present time Spare Time Gizmos has no plans to offer expansion cards for the SBC6120-RC.

==Other Questions==
===Are you planning any expansion boards for the SBC6120-RC?===
:No. The SBC6120 specifically lacks any bus or expansion connector, and it's intended to be a self contained, non-expandable, system.

===Are you from Massachusetts ? It says "Boston" with a pawprint on my PC board...===
:In this instance [http://www.facebook.com/BostoBeast Boston] is a "who", not a "where". Boston participated in the design reviews (he liked to sleep under the workbench) and I thought he deserved credit for his efforts. And yes, Boston (the city this time) was also the home of Digital Equipment Corporation. Unless you're one of those conspiracy theorists, it's just a coincidence.

User talk:Steve Gemeny

2013-03-05T13:08:35Z

Gizmos: Welcome!

User:Steve Gemeny

2013-03-05T13:08:35Z

Gizmos: Creating user page with biography of new user.

Director of Advanced Programs for Syntonics, LLC (www.syntonicscorp.com) managing engineering development of RF over Fiber systems for remoting antennas from radios for DoD applications and other advanced research projects under the SBIR program.

Earlier employment included a 10 year stint at Johns Hopkins Applied Physics Laboratory developing and building satellite ground station and ground systems for NASA science missions including TIMED (http://timed.jhuapl.edu/WWW/index.php)and New Horizons (http://pluto.jhuapl.edu/)

Longtime fan of the RCA CDP-1802, and an original member of the COSMACELF Yahoo Group.

Rather new to the SBC6120 and DEC PDP/8 world. Owner of a freshly operational SBC6120-RC, and soon to be joining the club of SBC6120 original hardware owners.

A Google search for AA3NM or Steve Gemeny should fill in any additional information needs.
Beware, there is a Steven W. Gemeny that is my cousin...
I am Steven E. Gemeny.

Picture frames

2013-03-05T13:07:44Z

Gizmos: Created page with "| | Steve Gibson has kindly provided these pictures of the picture fr..."

[[File:Steve's Frame 001.jpg|thumb|right|||450px|||]]
[[File:Steve's Frame 002.jpg|thumb|right|||450px|||]]
 
Steve Gibson has kindly provided these pictures of the picture frames he used for his SBC6120. The frames can be ordered from [http://www.larsonjuhl.com/p-1149-510bl.aspx?itemid=1963&CatId=137 Larson Juhl]

SBC6120/FP6120 Group Buys

2013-03-05T13:00:46Z

Gizmos: /* Where can I get more information ? */

== What is it ? ==

[[File:SBC6120 (VCFe Model).jpg|thumb||right||450px|||SBC6120 and FP6120 nicely framed]]
The SBC6120 is a replica of a 1960s/70s vintage DEC PDP-8 computer. It uses the Harris HD6120 "PDP-8 on a chip" CPU and started off as a single board computer the size of a 5-1/4" hard disk (and hence the name, "SBC6120"). Everybody wanted a lights and switches front panel, and a couple of years later I designed the FP6120 ("Front Panel 6120") that you see in the photos. The SBC6120 is fully operational and functional without the front panel - this is handy when assembling the kit, because it's possible to assemble and test the SBC6120 before the front panel is finished. The reality is that no one ever wants one without the other, and so the SBC6120 and FP6120 are always sold together as a set.

The HD6120 CPU used in the SBC6120 is the same one used in Digital's DECmate "personal" computers and is fully software compatible with a PDP-8/E. The front panel is fully functional and has the same complement of lights and switches as a real PDP-8/E. It measures 15" by 8-1/2" and is about 3/4ths scale when compared to a real PDP-8. The SBC6120 will run most software written for a PDP-8, including DEC's OS/8 disk operating system. The SBC6120 has an IDE disk interface that can be used with a real drive or (more commonly these days) a CompactFlash card or SSD.

To find out more, read the manuals for the [http://www.sparetimegizmos.com/Downloads/SBC6120.pdf SBC6120] and the [http://www.sparetimegizmos.com/Downloads/FP6120.pdf FP6120].

== Why a group buy ? ==

[[File:Debee and FP6120.jpg|thumb||right||350px|||Debee and the SBC6120]]
Originally Spare Time Gizmos stocked and sold SBC6120 and FP6120 kits as regular items, and many hundreds were sold that way. However some of the parts used are custom made, such as the faceplate, which is laser cut and silk screened, or the LED shadow mask, which is CNC machined. Many other parts, for example the paddle switches, have to be special ordered from the manufacturer even though they are "stock". All these items have minimum order quantities and can only be purchased economically in large batches. As orders for the SBC6120/FP6120 dropped off, the cost of carrying these items in inventory became prohibitive and Spare Time Gizmos stopped stocking the SBC6120/FP6120. The only practical way to sell them now is in batches of at least 25 to 30 units. Several such group buys have been done in the past, and this will be the fourth one.

== What do I get ? ==

The purpose of the group buy is to batch up all the "unobtainium" parts that you simply cannot buy anywhere else. To that end, Spare Time Gizmos will supply a partial kit for the SBC6120 and FP6120 containing[http://www.sparetimegizmos.com/Downloads/SBC6120-FP6120-Combined-Kit-Contents.pdf] -

* The beautiful FP6120 faceplate, silk screened in five colors and laser cut
* SBC6120 bare PC board (four layers, silk screened and solder masked)
* FP6120 bare PC board (two layers, silk screened and solder masked)
* One NOS HD6120 PDP-8 CPU chip
* A set of 20 paddle switches for the FP6120
* A custom machined LED shadow bar for the FP6120
* Three 64Kx4 SRAMs
* Two 27C256 EPROMs pre-programmed with BTS6120
* Five pre-programmed PLDs (three for the SBC6120 and two for the FP6120)
* Two stacking bus connectors used to connect the SBC6120 to the FP6120

'''That's all - the rest of the parts you will need to supply yourself'''. You should expect to spend another $100 to $200 for the remaining PCB mounted components, depending on how well stocked your parts box is. And of course that doesn't include an enclosure, terminal, disk drive or power supply. There is a complete parts list in the back of the [http://www.sparetimegizmos.com/Downloads/SBC6120.pdf SBC6120] and [http://www.sparetimegizmos.com/Downloads/FP6120.pdf FP6120] manuals, and there are also some more current lists, complete with DigiKey and Mouser part numbers, in the files area of the Spare Time Gizmos [http://groups.yahoo.com/group/sparetimegizmos/ Yahoo! Group].

If you prefer, a fully assembled and tested unit is available for an extra charge.

== How do I sign up ? ==

[[File:FP6120 Closeup.jpg|thumb||right||350px|||Closeup of the front panel]]
That's easy - visit our project page on [http://www.kickstarter.com/projects/sparetimegizmos/classic-pdp8-replica Kickstarter] and sign up as a sponsor. A pledge of $599 gets you the partial kit as listed above, and a pledge of $999 gets you an assembled unit ready for framing.

== Where can I get more information ? ==

* Wondering what's going on? Check the Project Updates on the [http://www.kickstarter.com/projects/sparetimegizmos/classic-pdp8-replica Kickstarter]page.

* Have a question? Check the [[Group Buy FAQ]] first.

* There are web pages for both the [http://www.sparetimegizmos.com/Hardware/SBC6120-2.htm SBC6120] and [http://www.sparetimegizmos.com/Hardware/SBC6120-2.htm FP6120].

* There are full manuals, including assembly instructions and parts lists for the [http://www.sparetimegizmos.com/Downloads/SBC6120.pdf SBC6120] and the [http://www.sparetimegizmos.com/Downloads/FP6120.pdf FP6120].

* Steve Gibson has some wonderful [http://www.grc.com/pdp-8/pdp-8.htm pages and videos] that explain both the original PDP-8 as well as the SBC6120 specifically.

* Steve has also provided details of the [[picture frames]] he used for his SBC6120s.

* There is a [http://groups.yahoo.com/group/sparetimegizmos/ Yahoo! Group] for builders of all Spare Time Gizmos kits. You can post your technical questions there. And be sure to browse the group archives too - there are lots of pictures and files related to past SBC6120 builds.

* There is a complete list of the [[additional parts required to finish the SBC6120]], including sources.

File:Steve's Frame 002.jpg

2013-03-05T12:57:59Z

Gizmos: Steve Gibson's SBC6120 Frame

Steve Gibson's SBC6120 Frame

File:Steve's Frame 001.jpg

2013-03-05T12:57:02Z

Gizmos: Steve Gibson's SBC6120 Frame

Steve Gibson's SBC6120 Frame

2013-01-28T17:52:53Z

Gizmos: /* What am I getting ? */

== News, Updates and Status Reports ==

* Looking thru my inventory after the recent SBC6120-RC buy, I see that I have thirty tested, known good, HD6120 CPU chips left on hand and that's left me pondering the question of "what would be a good use for them?" Given that the last group buy for the original was held three years ago, that seems like the obvious candidate. After calling my old suppliers and asking for quotes, I'm convinced that it's still possible to get all the parts necessary to build the original SBC6120/FP6120 combination, including the fancy paddle switches and custom faceplate. --[[User:Gizmos|Gizmos]] 11:24, 26 January 2013 (PST)

== What is it ? ==

The SBC6120 is a replica of a 1960s/70s vintage DEC PDP-8 computer. It uses the Harris HD6120 "PDP-8 on a chip" CPU and started off as a single board computer the size of a 5-1/4" hard disk (and hence the name, "SBC6120"). Everybody wanted a lights and switches front panel, and a couple of years later I designed the FP6120 ("Front Panel 6120") that you see in the photos. The SBC6120 is fully operational and functional without the front panel - this is handy when assembling the kit, because it's possible to assemble and test the SBC6120 before the front panel is finished. The reality is that no one ever wants one without the other, and so the SBC6120 and FP6120 are always sold together as a set.

The HD6120 CPU used in the SBC6120 is the same one used in Digital's DECmate "personal" computers and is fully software compatible with a PDP-8/E. The front panel is fully functional and has the same complement of lights and switches as a real PDP-8/E. It measures 15" by 8-1/2" and is about 3/4ths scale when compared to a real PDP-8. The SBC6120 will run most software written for a PDP-8, including DEC's OS/8 disk operating system. The SBC6120 has an IDE disk interface that can be used with a real drive or (more commonly these days) a CompactFlash card or SSD.

To find out more, read the manuals for the [http://www.sparetimegizmos.com/Downloads/SBC6120.pdf SBC6120] and the [http://www.sparetimegizmos.com/Downloads/FP6120.pdf FP6120].

== Why a Group Buy ? ==

Originally Spare Time Gizmos stocked and sold SBC6120 and FP6120 kits as regular items, and many hundreds were sold that way. However some of the parts used are custom made - for example the faceplate, which is laser cut and silk screened. Many other parts, for example the paddle switches, have to be special ordered from the manufacturer even though they are "stock". All these items have minimum order quantities and can only be purchased economically in large batches. As orders for the SBC6120/FP6120 dropped off, the cost of carrying these items in inventory became prohibitive and Spare Time Gizmos stopped stocking the SBC6120/FP6120. The only practical way to sell them now is in batches of at least 25 to 30 units. Several such group buys have been done in the past, and this will be the fourth one.

== What am I getting ? ==

The purpose of the group buy is to batch up all the "unobtainium" parts that you simply cannot buy anywhere else. To that end, Spare Time Gizmos will supply a partial kit for the SBC6120 and FP6120 containing -

* The beautiful FP6120 faceplate, silk screened in five colors and laser cut
* SBC6120 bare PC board (four layers, silk screened and solder masked)
* FP6120 bare PC board (two layers, silk screened and solder masked)
* One NOS HD6120 PDP-8 CPU chip
* A set of 20 paddle switches for the FP6120
* A custom machined LED shadow bar for the FP6120
* Three 64Kx4 SRAMs
* Two 27C256 EPROMs pre-programmed with BTS6120
* Five pre-programmed PLDs (three for the SBC6120 and two for the FP6120)
* Two stacking bus connectors used to connect the SBC6120 to the FP6120

You can find a complete list of exactly what is included here [http://www.sparetimegizmos.com/Downloads/SBC6120-FP6120-Combined-Kit-Contents.pdf].

That's all - ''the rest of the parts you will need to supply yourself''. You should expect to spend another $100 to $200 for the remaining PCB mounted components, depending on how well stocked your parts box is. And of course that doesn't include an enclosure, terminal, disk drive or power supply. There is a complete parts list in the back of the SBC6120 and FP6120 manuals, and there are also some more current lists, complete with DigiKey and Mouser part numbers, in the Spare Time Gizmos group files area.

THE PRICE FOR THIS PARTIAL KIT OF PARTS WILL BE $600.

== Where can I get more information ? ==

* There are web pages for both the [http://www.sparetimegizmos.com/Hardware/SBC6120-2.htm SBC6120] and [http://www.sparetimegizmos.com/Hardware/SBC6120-2.htm FP6120].

* There are full manuals, including assembly instructions and parts lists for the [http://www.sparetimegizmos.com/Downloads/SBC6120.pdf SBC6120] and the [http://www.sparetimegizmos.com/Downloads/FP6120.pdf FP6120].

* Steve Gibson has some wonderful [http://www.grc.com/pdp-8/pdp-8.htm pages and videos] that explain both the original PDP-8 as well as the SBC6120 specifically.

* There is a [http://groups.yahoo.com/group/sparetimegizmos/ Yahoo! Group] for builders of all Spare Time Gizmos kits. You can post your technical questions there. And be sure to browse the group archives too - there are lots of pictures and files related to past SBC6120 builds.

* And lastly you can [mailto:webmaster@sparetimegizmos.com email me directly] for payment and shipping questions. Please don't email me for technical questions - post those to the Yahoo group so that we can all hear what's said and participate. If you haven't already joined this group then you should, and while you're there check out the group archives.

SBC6120/FP6120 Buy 2013

2013-01-28T17:51:09Z

2013-01-26T19:49:11Z

Gizmos:

'''Welcome to Spare Time Gizmos' documentation wiki.'''

This wiki is for documentation of all Spare Time Gizmos' projects. User contributions are welcomed.

== Current Group Buy Information ==

== Errata, FAQs and Additional Information ==
* [[Elf 2000]]

== Wiki Manuals ==
* [[SBC6120-RC User Manual]]
* [[S6100 Design Notes]]

== PDF Manuals ==
* [http://www.SpareTimeGizmos.com/Downloads/SBC6120.pdf SBC6120 User Manual]
* [http://www.SpareTimeGizmos.com/Downloads/FP6120.pdf FP6120 User Manual]
* [http://www.SpareTimeGizmos.com/Downloads/Elf2k.pdf Elf-2000 User Manual]
* [http://www.SpareTimeGizmos.com/Downloads/vt.pdf VT-4/5/6 User Manual]

SBC6120/FP6120 Buy 2013

2013-01-26T19:24:35Z

Gizmos:

== News and Updates ==

--[[User:Gizmos|Gizmos]] 11:24, 26 January 2013 (PST)

Looking thru my inventory after the recent SBC6120-RC buy, I see that I have thirty tested, known good, HD6120 CPU chips left on hand and that's left me pondering the question of "what would be a good use for them?" Given that the last group buy for the original was held three years ago, that seems like the obvious candidate. After calling my old suppliers and asking for quotes, I'm convinced that it's still possible to get all the parts necessary to build the original SBC6120/FP6120 combination, including the fancy paddle switches and custom faceplate.

== Introduction ==

If you came to this page then you're probably anxious to buy one, but please read the rest of this information first. The instructions for ordering one are down below, I promise, but there's a lot of other information that you should know first. I recommend that you read everything, maybe more than once, just to be sure you understand what you're getting and to ensure that you aren't disappointed.

Please don't email me directly for information about this order unless you have some deeply personal thing that you need to discuss. All other discussions about the SBC6120/FP6120 should be directed to the Spare Time Gizmos Yahoo! group so that we can all hear what's said and participate. If you haven't already joined this group then you should, and while you're there check out the group archives. There are lots of pictures and files related to past SBC6120 builds.

== What's an SBC6120 ? ==

== What am I getting ? ==

SBC6120/FP6120 Buy 2013

2013-01-26T19:02:50Z

Gizmos: Protected "SBC6120/FP6120 Buy 2013" ([edit=sysop] (indefinite) [move=sysop] (indefinite))

January 2013 SBC6120/FP6120 Group Buy Information.

SBC6120/FP6120 Buy 2013

2013-01-26T19:02:42Z

Gizmos: Created page with "January 2013 SBC6120/FP6120 Group Buy Information."

January 2013 SBC6120/FP6120 Group Buy Information.

Main Page

2013-01-26T19:01:26Z

Gizmos:

'''Welcome to Spare Time Gizmos' documentation wiki.'''

This wiki is for documentation of all Spare Time Gizmos' projects. User contributions are welcomed.

== Current Group Buy Information ==
* [[SBC6120/FP6120 Buy 2013]]

== Errata, FAQs and Additional Information ==
* [[Elf 2000]]

== Wiki Manuals ==
* [[SBC6120-RC User Manual]]
* [[S6100 Design Notes]]

== PDF Manuals ==
* [http://www.SpareTimeGizmos.com/Downloads/SBC6120.pdf SBC6120 User Manual]
* [http://www.SpareTimeGizmos.com/Downloads/FP6120.pdf FP6120 User Manual]
* [http://www.SpareTimeGizmos.com/Downloads/Elf2k.pdf Elf-2000 User Manual]
* [http://www.SpareTimeGizmos.com/Downloads/vt.pdf VT-4/5/6 User Manual]