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Searching for NEC PC-8001A software & hardware

vwestlife

vwestlife

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My dad had a NEC PC-8001A in the 1980s, and it was the first computer I used when I was a kid. That one is long gone now, but finally I was able to get another one recently. Unfortunately all I have is the main keyboard unit. So, I am looking for any software for it, as well as peripherals like the PC-8012A expansion unit -or- the Renaissance Technologies "The Wedge" aftermarket expansion base, and the PC-8031A dual floppy drive unit. One web site claims only a few thousand of NEC PC-8001s were sold outside of Japan, so these may prove rather difficult to find!
 
I don't know of any software.

Strangely enough I do have a screen for this model. Years ago I bought it off our Trade Me site "as is" thinking it was a standard green screen monitor. I have no idea if it works. No raster appears when plugged in, but it could need activating from the computer itself like the IBM 5151 screens. Do you know if it does? Or it could just be broken.

Tez
 
The PC-8001(A) has two DIN video ports: monochrome composite and color RGB.

The composite port uses the same pin for video as the Dragon 64, so luckily the video cable I use for my Tano Dragon works fine. But be careful -- the pin that the Dragon uses for audio output, the NEC has +12 volts DC coming out of! (The NEC only has a little beeper built in, and no audio output.) Tez, maybe this voltage is the trigger to turn the NEC monitor's raster on?

The color output is 8-color 15 kHz analog RGB (quite advanced for a computer introduced in 1979!). With the right cable, it would work with my Commodore 1084 monitor, or my Mitsubishi Diamond Scan AUM-1381A.

Renaissance Technology also sold an RGB-to-color-composite converter (and RF modulator) for the PC-8001A, pictured below. It has an audio input because it was designed to support Renaissance's "The Wedge" add-on, which also provided a 3-voice sound chip and four (yes, four!) Atari 2600-style joystick ports.

rgbtocomp.jpg
 
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The NEC floppy drive unit had some unique features, as Creative Computing wrote:

"When power is applied to the unit, the drives do not rotate. The motor goes on only when a read or write operation is initiated by the computer. However, the drive then continues to spin for 2-1/2 minutes, so subsequent disk operations are immediate and do not require a wait while the disk gets up to speed. If the drive is not accessed for 2-1/2 minutes, the motor shuts down. We judge this an excellent way to speed disk response time while saving wear and tear on the drive motor. A red LED indicator on each drive indicates when a read or write operation is taking place; these lights glow at 20% of full intensity when the drives are in the standby state."
(from http://www.atarimagazines.com/creative/v9n11/28_NEC_PC8800_personal_comp.php )

I distinctly remember that long motor after-run from when I used the NEC as a kid, writing book reports for school in WordStar. After a few minutes, the drive motor would stop, leaving me to write in silence... until I went to save the file, then the motor would whirr back to life.
 
I was just about to post a new thread 'Calling any PC-8001 owners' when I saw your thread - uncanny!

I am keen to make contact with any owners world-wide, to build up information and a software / documentation library.

I have just created a few pages on my machine, check out the links as there are quite a few Japanese sites:

http://vintagecomputers.site90.net/nec/index.htm

I have it working with a mono monitor currently, and am thinking of making up a lead for a colour monitor, only problem it is RGB + H and V sync, my Microvitec can do this but is wired for RGB + composite sync so needs tweaking.

I am interested in finding any cassette based software.

Please either reply to this thread if you are an owner (or just interested), or pm me if you wish to remain anonymous.

Regards,
John

PS When I first got an HP-85 there was a similar lack of software available on-line, now there is a wide range, nearly all of which can be found at the HP Computer Museum site. I hope by promoting the PC-8001 a similar world-wide group will pool resources and lead to a healthy collection of software.
 
I've two 8001 machines, an original PC-8001 and its brother PC-8001Mk2. Sadly, IIRC I don't have any software to feed them, I think that I only have some 6001 titles lying around :-(
I also have the PC-8031; but the data cable is severely damaged. I need to check this one of these days.

About the RGB connection, I commonly use the 1084 as vwestlife has suggested, the cable is pretty easy to build and it's shared by dozens of 80's japanese computers. Of course it uses separate syncs; so having a composite sync monitor means that some electronics would be needed.
 
I have one of these:

thm_NEC_PC-6001A_sn3400005C_nameplate.jpg


I know, I know not very helpful, you usually don't hear much about the 6001. :)

thm_NEC_PC-6001A_sn3400005C-b.jpg
 
The PC-6001A was also known as the "NEC Trek", and was a lower-cost home computer with color graphics, AY3 sound, a cartridge port for games, and Atari-style joystick ports. It was similar to, but not compatible with, the MSX computers that later became popular in Japan.
 
I would love to find a real NEC-Trek, it has a much better keyboard than it's japanese counterpart :)
It's indeed similar to the MSX machines...internally; but curiously, it looks extremely close to CoCos as it has a 6847 as graphic processor.

About the 8001 series, has anyone a PC-8001Mk2SR?. AFAIK, it has much better specs than their predecesors.
 
vwestlife said:
The PC-8001(A) has two DIN video ports: monochrome composite and color RGB.

The composite port uses the same pin for video as the Dragon 64, so luckily the video cable I use for my Tano Dragon works fine. But be careful -- the pin that the Dragon uses for audio output, the NEC has +12 volts DC coming out of! (The NEC only has a little beeper built in, and no audio output.)

The color output is 8-color 15 kHz analog RGB (quite advanced for a computer introduced in 1979!). With the right cable, it would work with my Commodore 1084 monitor, or my Mitsubishi Diamond Scan AUM-1381A.
Click to expand...

Hi,
I hooked my PC-8001BE up to an oscilloscope this evening to take a look at the video outputs. I used the pin-outs as per the old-computers.com site, these seemed to be correct when looking at the back of the computer facing the sockets.

The black & white output was fairly normal, +0.7V to -0.3V (1V p-p). The vertical/frame rate is 60Hz and the horizontal/line rate is 15.75kHz, so this is standard NTSC. This is not common in europe (PAL specifies 50Hz / 15.625kHz) so I will need a NTSC-type monitor. Most mono monitors can be adjusted to 60Hz but not all.

The color sockets were quite odd. These socket has:

V sync = 60Hz negative going pulses (16.7ms between pulses, TTL levels, 0V to 4.1V)
H sync = 15.75kHz negative going pulses (63us between pulses, TTL levels, 0V to 4.1V)
Color clock = 14.3MHz (ie 4 times the NTSC 3.579545MHz color carrier), positive going pulses (70ns between pulses, from -2V to +8V)
RGB = waveform going from -8V to +16V (24V p-p)

As the power on screen is mostly blank the RGB signals are long periods of 0V with short bursts of signal. Not sure why the voltage goes over such a large range, maybe it is designed for some sort of terminating network (eg a 1kohm resistor in series feeding a 100 ohm resistor to ground would give 2V p-p, or a 150 ohm resistor in series feeding a 75ohm input)?

Also both video sockets have a +12V pin for powering modulators (or turning on monitors).

I would be wary of connecting the color output straight into a prized multisync monitor without checking it out first.

Maybe vwestlife could open up his RGB to composite converter and have a look at the RGB input?

I found a similar adapter (well NEC computer RGB in to component video out) here:

http://tulip-house.ddo.jp/digital/DIGITAL_RGB_COMPONENT/english.html

Regards,
John
 
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The color output is 8-color 15 kHz analog RGB (quite advanced for a computer introduced in 1979!). With the right cable, it would work with my Commodore 1084 monitor, or my Mitsubishi Diamond Scan AUM-1381A.
Click to expand...

It would work using the digital input (8 pin) of the 1084; as 1980s_john has already checked, the levels are TTL, not analog. You can find the cable pinout here, it's a japanese standard used by most of the major companies.

Using some resistors and combining the syncs you can also use a SCART TV or any other analog device. No idea about the US TV sets...

Later I'll try to post some pics of my MkII hooked to my 1084.
 
My PC-8012A expansion unit arrived today. This thing would eat the TRS-80 Model I expansion unit for lunch -- it is solid metal and very sturdily built! It arrived with the 32K RAM card and what appears to be a dual RS-232 serial port card (with 8251 UARTs and ribbon cables to two male DB25 ports on the back).

Both it and the PC-8001A main unit have a sticker saying that it was "marketed pursuant to a waiver of FCC rules Part 15 Subpart J; operation of this computer in a residential area may cause objectionable interference to radio and TV reception" -- which is strange because the expansion unit looks extremely well shielded, with a metal box around the power supply, ground tabs around all the card edge connectors, and even a metal screen over the ventilation holes in the cover.

Although I don't have the disk drive unit to really test it yet, it does seem to work; upon turning on the PC-8001A with it connected and turned on, there is an extra delay before the BASIC screen appears, presumably during which time it's trying to access the (non-existent) disk drive for a boot disk.

I also got some manuals with it, for the PC-8001A computer, an N-BASIC manual and quick reference guide, and a manual for the expansion unit, with very detailed specs and info for programmers on how to address its expansion bus and extra RAM.

100_0561.jpg100_0548.jpg100_0549.jpg100_0550.jpg100_0553.jpg
 
Excellent news! Glad you have a load of manuals, I am in contact with someone in the UK who may have some - not sure yet. Did you ask the seller about any floppy disks?

Please can you document the cable between the PC-8001 and PC-8012, this I lack :-(

The extra RAM card should be recognised by the PC-8001 base unit (if jumpered correctly), I think the Basic command is something like 'PRINT FRE(0)'.

Looks like your RS232 card is non-NEC - interesting.

According to this site (best viewed in Chrome for auto-translation):

http://web.archive.org/web/20120702141615/http://www 2.odn.ne.jp/~haf09260/Pc80/EnrPc.htm

the base unit has an RS232 port presented as a 16-pin DIL socket, so needing a special lead to connect it up. Can you look this up in your manual please,I would be interested in figuring this out eg:
- port address of interface from Z80
- routine in Basic / assembler to drive serial port
- dumping ROM out to serial
- boot strapping disk drive via serial port

Regards,
John
 
Hi there fokes,

Well looking through my bits, I have a PC-8001B yes that is a B on the end.

Also have the PC-8021B I/O unit still packed in the original box. It has only an expansion memory card installed.

And it has the interface cable to the PC-8001B. Will try and post some information on cable to aid anyone wishing to make one.

I will get both powered up by end of January this year hopefully.

Then make a decision if they will stay in my downsized collection or if I will sell them.

regards
David
 
Funny how NEC renamed their machines with tons of suffixes; I'd finally find a "NEC-Trek"; but it was not the real "A" one; but the "B" one. There's not too much info in the net about the PC-6001B.

Btw, that PC-8012A looks fantastic, any progress since then?. In the last years I was able to repair some expansion disk units for the 8001 and find a lot of software, nice machine all in all :)
 
jltursan said:
Funny how NEC renamed their machines with tons of suffixes; I'd finally find a "NEC-Trek"; but it was not the real "A" one; but the "B" one. There's not too much info in the net about the PC-6001B.
Click to expand...

The A on the end means it's the American version. I'm not sure what the B indicates -- maybe British version, or just the next letter after A? :)

I'm still looking for a PC-8031A Mini Disk Unit. There was one on eBay for a long time, but it came bundled with another I/O Unit and a $400 price tag:

http://www.ebay.com/itm/221972663119
 
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