PDA

View Full Version : General Retro Carputer Project - Staying true to 1981



DrJeff
03-31-2013, 11:56 PM
I had played with the idea of fitting a 7in tablet into the D just where the stock vents are, however it just didn't look right. While I've updated lots of other things in the car the touchscreen tablet was out of place. I figured that if I'm going to drive a 1981 car that I should fit a 1981 computer. Since I spent my teen years in N. Ireland I was fan of Clive Sinclair and his ZX81 computer. (I believe it was marketed in the USA as a Timex.) It has 1k (that's 1024 bytes) of RAM (random access memory for the kids) with a black and white output display of 24 lines and 32 characters wide.

The ZX81 computer takes 9v dc, so I had some work getting a transformer that would step down to 9v rather than the more common 5v. Since I removed my center vents I had plenty of space behind the computer to fit the transformer. I just stuck the transformer to the bottom of the center console metal bracket, which also acts as a heat sink.

I kept my ASI radio unit to act as the program loader. The ZX81 can connect directly to the audio out on the tape deck. I had some old program tapes and unbelievably these loaded first time onto the ZX81. You would think that after 30 years magnetic audio tape would give up, but I guess the baud rate was so low that there was still enough tone on the tapes for the computer to pick up the code. It still took a long time, probably 10 minutes to get my first program loaded. I can't save any programs/data from the ZX81 as the ASI radio doesn't have a record button. It's possible, but I'll have to save that option till next year.

I wrote more programs on the ZX81 than I can remember, so it was easy to pick the Sinclair Basic back up again. Of course I had to forget a whole bunch of modern programming things that I've learned from 1981 until 2005. The ZX81 was advertised as being able to run a nuclear reactor. I don't think anyone expected that someone would actually run a nuclear reactor with it (although in the UK - you never know). If it was good enough for a nuclear reactor it was certainly going to be good enough for the Delorean.

I couldn't hook of a 1981 monitor (or as we called them then 'TVs') for a display, so I mounted a small 24 line by 32 character LCD display on the upper side of the passenger's sunvisor. I thought about putting it on the driver's sunvisor, but that might be worse that texting and driving, so to be safe it's on the passenger's side. I've found that if my wife's driving and I'm using the ZX81, I really need to wear my reading glasses as the display is just a little too close. A bit of a compromise but another good reason to have the display in the passenger's sunvisor, as driving with my reading glasses on would be bad.

The project is not 100% finished yet, but I'm really pleased with the way it is turning out. The few folks that have seen it so far think it is really cool, and very retro.

I'll post full instructions only with photos on this retro carputer project.

17813

Have a fun day!

Michael
04-01-2013, 12:14 AM
Definately post more pics! I am so fond of vintage computers.

vwdmc16
04-01-2013, 01:01 AM
Very interesting but what exactly could you do with it? Besides run a nuclear reactor. Hmm you would think Doc brown would have had one to control his.

What are the controls like? a simple key board?

SamHill
04-01-2013, 10:29 AM
Steering wheel needs a calculator.

LordFly
04-01-2013, 12:27 PM
Not sure if legit post, or April Fools joke ;)

17822

Dangermouse
04-01-2013, 12:42 PM
Uses radio/cassette to load programs, yet unit absent in pic.

Mmmmmmmmm

Spittybug
04-01-2013, 02:04 PM
Not sure if legit post, or April Fools joke ;)

17822


+1

DMC81
04-01-2013, 02:31 PM
Not sure but to me the keyboard looks photo shopped.....

Nicholas R
04-01-2013, 05:47 PM
Lol, this is one of the better things I've seen today. Well played :thumbup:

dmc3130
04-01-2013, 06:52 PM
Not sure but to me the keyboard looks photo shopped.....

++++++++1 :what_the:

DrJeff
04-01-2013, 11:03 PM
You got me :) Glad you had fun with the story.

I am fitting a Google Nexus 7in tablet. It fits perfectly over the area previously occupied by the center vents (now in the kneepads) and the radio. The amp sits behind in the area left by the center vents.

kobachi
04-07-2013, 11:47 AM
You got me :) Glad you had fun with the story.

I am fitting a Google Nexus 7in tablet. It fits perfectly over the area previously occupied by the center vents (now in the kneepads) and the radio. The amp sits behind in the area left by the center vents.

Do you have pics or a post somewhere of the A/C modification you did? I'm interested in this.

DrJeff
04-07-2013, 03:37 PM
Do you have pics or a post somewhere of the A/C modification you did? I'm interested in this.

I'm going to write this mod up properly... but in the meantime...

1. Removed the center vents (removed a bunch of other bits first to get at this)
2. Removed the radio. You could still do this with the radio left in, or even go for a double-din radio, but I pulled the radio out to go tablet.
3. Molded heavy rubber over the center vent outlets and secured the rubber with cable ties. This makes the vents out of the side of the air box as the only outlet. The side vents used to feed only the door vents.
4. Removed the door vents and all the piping leading to them. Now the doors have a piece of walnut burlewood in place of the vents.
5. Bought... 2 1/4 AC vent pipe, lots of large cable ties, vents for the kneepads. You have to be careful selecting the vents because the space available inside the keedpad is limited.
Note: I didn't end up using the vents I bought for the kneepads as they were very small and looked too modern. Instead I used the vents I pulled from the doors and the center vent. I had to chop the center vent in half and do some plastic work on the edges of the center vents and door vents to make them look symmetric.
6. Take off all three kneepads and cut holes for the vents. Need to be sure you can place the vent, especially on the passenger kneepad as you need to be to the left and right of the glovebox to give the air vent some room to meet the back of the vent. The vent at the LH side of the passenger kneepad was the most challenging as the glovebox doesn't leave much of a gap.
7. Fit the vents in the kneepads
8. Connect the side vent outputs from the airbox to the vents. I used one of the rubber (square) connectors from the center vent to connect to the side vent on the driver's side. I removed the solid pipe that ran over the driver's column and replaced the assembly with AC hose. Since each airbox output will feed two vents, you will need a Y splitter. Since I was also using the stock vents I needed to design and have 3D printed some connectors that allowed the 2 1/4 AC pipe to connect to the back of the vents. Modern vents will tell you what size of pipe they will accept.
9. Since I decommissioned the door vents AND I was also recovering every cabin surface, I took the opportunity to close off the vent holes in the door panels and in the sides of the outer kneepads.

here are some photo's

17995179961799717998179991800018001180021800318004 18005

So overall very happy with the vents (repositioned stock vents) and the airflow. Not cooling the sides of the doors means more air for the passengers. I was a little worried that the driver would only have vents situated low in the kneepads, but it hasn't been a problem. The cool air is forceful enough to blow pas the steering wheel and up to the driver's face.

Things I would do differently?
- The vents from the doors are long and the plastic along the side tends to collapse inwards. This restricts the movement of the vent flaps. It was noticeable on the doors. but in normal usage you had them faced only one way. When they are in the kneepads it is more likely that you'll redirect them up or down and you feel the restriction from the design flaw. Just a niggle.
- Doing the plastic work on the vents to make them symmetric (after being halved and respositioned from the door) was a pain. I'm still considering designing and printing up some new 'facias' for the vents, probably in 3D printed stainless steel.

kobachi
04-07-2013, 03:47 PM
Holy crap, Jeff. I get the feeling you've done a mod or two before ;)

Looks like you've recovered your dash/glovebox lid as well. Very plush looking interior you have there =D

Thanks for the info!