(this post keeps turning up if I delete it, so let’s leave it here for now)
Instagram filter used: Lo-fi
(this post keeps turning up if I delete it, so let’s leave it here for now)
Instagram filter used: Lo-fi
I’d been having no luck getting the SD card working on my Zeta. I got help on the mailing list, and uploaded a new 512KB Flash ROM image (via XMODEM and floppy; teh slow!). So now I have two multi-megabyte drives on my CP/M computer — whee!
You have no idea how good it was to see that message come through over the serial link. The Zeta worked first time!
Here’s the board, fully populated:
I still have to put it in a proper case. A visit to Above All Electronics did result in getting a floppy drive (and most importantly, 3½” 1.44 MB floppies …) and all the cables, so I’ll add that later. But for now, I’ll try to remember how CP/M works …
Please excuse horrible blurry photo, but I think all the soldering is done —
This adds the crystal sockets, the 32.768 kHz RTC crystal, the status LED(s) and the reset button.
A whole new board I soldered up is the Mini-PPISD. It adds (slow) SD card storage to an SBC board:
Man, but those surface mount SD card pads are a pain. I had to get flux on the PCB pad and the bottom of the SD connector, load a little blob of solder on the iron, then warm up the pad and roll the solder into place. It made a satisfying little Zsht! noise as the flux burnt off, and the molten solder got drawn under the pad by capillary action.
Next up is checking the power and ground continuity, adding the chips, building a null modem (grr; I hate RS232, really) and finding a case. I may already have one, but I may forage at Above All to get a 3½” floppy drive and enclosure. I definitely have an old Turbo/reset button from an XT that would make a great reset breakout.
Just waiting for the full-can oscillator sockets (and most of the chips) to arrive from Mouser. I could have used 14-pin DIP machine pin sockets, as Sergey was thoughtful and had all of the holes drilled.
Most of the big sockets need to be fully soldered, as at the moment they’re just tack-soldered at the corners. Maybe I’ll put on some dronecore and have a meditative time with the Sn-Ag tonight. I’ll be glad to get the flux off the board, though: it’s not my usual stuff (which is Kester #951; no clean ftw), and what I’m using is smoky and a bit gummy. It does make nice bright joints, though, which is never 951’s strong point.
This might be my last post on mini-printers, as I’ve found a driver that just works with CUPS on Raspberry Pi. It also works on Ubuntu on my laptop, and should work (though untried) on Mac OS. You’ll have to build it from source, but it’s not too hard.
The hard part is working out if your thermal printer will work or not. There are many out there, and they’re all slightly different. If they support the ESC/POS bitmap command GS v 0 on 58 mm wide paper, they should work. The ones I’ve tested are:
The following should also work, but haven’t been tried:
Known not to work:
If you have a manual for your printer, check it to see if it prints bitmaps by sending a three byte header of 29 118 48 (or 1D 76 30 in hexadecimal). If you’re not sure, try it with a small test image, and be ready by the power switch …
The driver is meant for a ZiJiang ZJ-58 printer, and lives here on Github: klirichek/zj-58.
Now read and follow the Building & Installing section of the README, and do what it says. I’ll wait …
This bit is much more graphical. You’ll need the system-config-printer package:
sudo apt install -y system-config-printer cups
Open up the printer settings window (Preferences → Print Settings):
Select the Add icon, and the New Printer window opens:
The POS5890U shows up as “Unknown” on my USB port, as Linux doesn’t know the name of this device from its USB ID.
Update (for the slightly desperate): In the land of “Things have changed!“, my Catex printer isn’t/wasn’t showing up at all. I had to resort to this in the Enter URI option:
parallel:/dev/usb/lp0 seems to work. Another option might be looking at the output of
sudo /usr/lib/cups/backend/usb
which suggests that usb://Unknown/Printer might work too. (All of this might need to have been preceded by
sudo usermod -a -G lp pi
and a logout or reboot; I did say this was for the slightly desperate …)
If the above doesn’t apply, your printer might have an known ID, or show up as a serial port. Select the right one, and click Forward:
Here, I’m really pleased that the driver is for a Zijiang unit, as it’s conveniently at the end of the list. Click Forward …
No options here, so again, Forward …
I changed the name from the default ZJ-58 to the more unixly zj58. You don’t have to, but either way, Apply the changes.
And there it is, registered as a printer!
Most printers expect paper wider than 58 mm, but mini-printers can’t do that. To tell the system about paper sizes, right click on the printer’s icon, and change the printer settings:
A test page might print properly now, but you should probably go into Printer Options first:
You do want to set the media size to at least 58 × 210 mm. This is just the longest strip it will print in one ‘page’; if your print is shorter, it won’t waste extra paper. You can choose longer prints, but not wider. The default assume your local standard paper size which —be it A4, Letter, or whatever — will not be what you want here. Hit OK.
You could print the self test page, but it’s long and boring. If you’re fairly sure your printer will be supported, try this scaled PDF version of the Raspberry Pi Logo: raspberry-pi-logo. Printed and scanned, it came out like this:
Not the best rendition, but not bad for a $30 receipt printer. My test image came out like this (iffy scan, sorry):
I haven’t covered the intricacies of setting up serial port connections here; maybe another time. Also, there’s a short delay (maybe 10–20 s) between selecting Print and the printer coming to life. CUPS is pretty complex, and is doing things in the background while you wait.
(Seeing as I use their logo prominently up there, I should totes acknowledge that “Raspberry Pi is a trademark of the Raspberry Pi Foundation”. Also, I couldn’t have done all this without the support of Reed Zhao. Though Reed has moved on to bigger things and doesn’t sell printers any more, his help — not to mention the generous gift of a couple of printers — was very welcome.)
→ you might also be interested in my notes on mini-printers and Linux – it has some manuals too.
That’s all but one of the capacitors in. The big chip sockets are soothing to solder.
Apart from the bits I got in a frantic dash between Supremetronics and Creatron on College, the rest is coming from Mouser. Taking the advice of someone who should know better, I’ve ordered a made-in-DDR UA857D MME chip, since Z80 CTCs are back ordered. Sometimes, it’s good to have chips older than your colleagues …
Instagram filter used: Lo-fi
Scored this cheapo USB printer on eBay: “High-speed 58mm POS Dot Receipt Paper Thermal Printer USBâ€. It identifies itself as a CATEX Technolog [sic] POS5890U, with a USB vendor:product ID of b000:0410. After a bit of random fiddling, it shows up as /dev/usb/lp0 on a Raspberry Pi. After turning off CUPS (as it nabs the device, not even letting root near it), you can print images up to 384 dots (48 mm at 8 dots/mm) wide using the ESC-POS GS v 0 command. You can use my esc-pos-image.py script if you wish, and if you need a test image …
(The photo is of Marie Doro; proto-goth 1902 style.)