Zenith Z-180

[Caluser2000]

Just been out in the shed and under one bench top was this wee beauty. A Zenith Z-180 XT laptop. Model ZWL-183-93. Manufactured in 1987 it came in two versions as far as I can tell. A double 3.5" 720k fdds or one 3.5" 720k fdd and hdd version. I got the later. The fdd bays are designed to pop up when in use which is a nifty feature. It has a number of external ports side and rear. The rear ports are ext. 5.25" fdd, RGB monitor output serial and ltp ports. The side are Line, Tele and a few others with power inlet and on/off switches on the opposing side. Has a built in modem. The hdd has long met its maker and looks like a previous owner has tried to pry the hdd up when the hdd is remove by removing two torx security screws and sliing the hdd from out the rear of the system. It came with two very comprehensive manuals as they did back then and the original MS Dos 3.21 system/boot disc. Getting any info online about Zenith systems is like pulling teeth. Also have the original registration cards as a bonus. Underneath is a bank of dip switches. With these you can select speed(4.77 or 8Mhz), A: drive location(Ext or internal), display width 80 or 40 characters), display type(LCD or CRT), and drive count(1 to 4-can be 3.5"or 5.25"). The back port cover catch is broken so flops about. A bit of fridge magnet and a small piece of steel or velcro will sort that out.

On boot press ESC and eventually you get a prompt to press ? and then press enter. The diagnostic monitor rom will provide you with a whole host of options, one being B 0 then press enter to boot off the fdd. You can enter the Monitor mode ant time by pressing the CTRL-ALT-INS keys at the same time. Once done you are given a few optiosn from the original boot disk. Selecting N puts you at the Dos prompt.

The carry case is currently in the clothes washer for cleaning and yes I did check it was empty before hand retrieving a number of 720k floppies in the process.

This system will compliment my Z286LP Plus quite nicely. That's been solid and I'm sure this will be too looking at the way it is built. I'll hook it up to one of my P166MMX test rigs linux installations for some serial dumb terminal fun using the Banana Dos terminal emulator.

 

[Caluser2000]

A bit more tinkering with it. The hdd cover does indeed pop up. I accidentally push in the right area and the cover popped out. Also at the back where I thought was the place to remove the hdd was what looks like an 8-bit ISA expansion slot but it is not document in the books I have. I grabbed out an old 8-bit joy stick card to compare the size and is the same size and pin arrangement. Possibly for diagnostic purposes maybe? Until I find out a bit more about it I'll leave it alone to not cause any damage.

 

[Caluser2000]

Opening up the beast was quite straight forward 2 screws in the rear port bay and 2 in the battery bay. The front portion had some sort of glue across it but that was easy to seperate with the finger nail. I suspect there was a 5th screw bottom center front but that was missing. Plenty of cable just the flip the top position over and only one connect heeded to be disconnect which hooked up section containing the leds. Very clean inside no dust at all. Also the battery pack seems to be charging fine. It has a keyboard connection for standard XT class desk top keyboards.

Time to remove the hard drive.

 

[Caluser2000]

Ok hard drive is out. It's a 3.5" JVC Model JD38224R00-1. Zenith P/N EA4779-003 with a hdd connector I've never seen before. It's well damped with bumpers in all corners and housed in a protective cage. No web search matches.

Looking more like that large connector in the back is for an external hdd.

 

[neosunrise]

This looks similar to my HP Portable Vectra CS. The hdd is pretty much the same as mine, which is a pain in the rear. My has a stuck head and it is basically impossible to find a replacement.

 

[Caluser2000]

modem7 has the Z-180 series Owners Manual in PDF format http://www.minuszerodegrees.net/man...s/Zenith Z-180 PC Series - Owner's Manual.pdf Seems to be some variances compared to mine. As I mentioned earlier info on Zenith/Heath stuff. It is like pulling teeth. Very little information out there. which is unusual since they catered for the educational and Govt. departments primarily. it's like everything was slammed in a vault.

The drive cage has a p/n of JD-3824R0Z0 and found this old vcf thread http://www.vcfed.org/forum/showthread.php?17490-MFM-Drives-Compact-Flash-Replacements/page2

 

[Caluser2000]

All put back together again except the isa looking conection cover. I'll replace the torx security screws with phillips head screws for ease of access in future. Just going through all the programs on the Zenith supplied supplied floppy. Lots of goodies. Quite amazing how much stuff you can get on a 720k disk. The most interesting one for me is zcom. It is a Zenith supplied serial file transfer program/terminal emulator, used to transfer programs system to system via serial port direct or via dial-up modem. Now this is 1987 well before MSs interlink/interserv programs. You can set a system up as a zcom server or use it as a client to transfer files. Handy for future use and will compliment the mtCP suite nicely.

 

[Moondog]

They were an easy system to work on, except when the battery or the ceramic resistor that's part of the charging circuit would melt the side of the case. Since this was physical damage, the service contract we had covered it, so we have to replace the entire tub underneath the pc and transfer the serial number label.

 

[Moondog]

You're lucky to get a JVC drive. The ALPS drives were notorious for seizing up. The HDD cover was not meant to pop up like the floppy. IIRC the "legs" were melted on the ends to keep the cover in place. Funny thing was a little force would snap that plastic burr off. I can't picture it, but did that model have a removable cover to install a modem?

 

[Caluser2000]

Yeah there's a cover on the bottom right hand side held in by one screw. There's a few other connectors on the mobo unused. Do you know what the iSA looking connector at the back was for Moondog?

 

[GiGaBiTe]

This looks similar to my HP Portable Vectra CS. The hdd is pretty much the same as mine, which is a pain in the rear. My has a stuck head and it is basically impossible to find a replacement.

I did a bit of googling and found a guy that has a few blog posts about reverse engineering the connector. Turns out its a modified ST-506 protocol to better fit laptop use.

https://knm.org.uk/blog/2017/04/the-jvc-26-pin-hard-disk-interface-part-1/
https://knm.org.uk/blog/2017/05/v86p-expansion/
https://knm.org.uk/blog/2018/09/the-jvc-26-pin-interface-part-3/

And this place makes a "we do everything" board which has support for the weird 26 pin JVC controller.
https://www.drem.info/technical-specs

It's not cheap though..

The guy also mentioned the connector that the disk controller plugs into is a slightly modified 8 bit ISA bus, so it may be possible to make a custom ISA board to have XT-IDE support.

 

[Caluser2000]

I've acquired another one of these wee beauties. This time it is a twin 720k fdd version. https://www.trademe.co.nz/a/marketplace/computers/vintage/listing/3087231157?bof=Dc3WGI68

 

[rfka01]

Hi Caluser2000 , it would be great if you could read out and post the BIOS ROMs of your Z-180's. I'd love to include the machines in the MAME emulator.
There's no need to crack them open (unless you decide to and have an EPROM reader anyway) - some DEBUG magic will do:
http://mess.redump.net/dumping/dump_bios_using_debug

Thanks
Robert