VeriFone Tranz 330

VeriFone Tranz 330

Here we have a common credit card terminal based on a Z80 chipset running the earliest published BASIC port of Eliza from the July 1977 issue of Creative Computing. I replaced the terminal’s ROM with Microsoft BASIC and added in stuff to mirror the last printed line to the VFD.

The VeriFone Tranz 330 was a very popular, possibly iconic credit card terminal that was produced almost unchanged from 1985 through the mid ’00s. Inside is a Zilog Z80 running at 3.57MHz (colorburst!), 32K RAM and 32K EPROM, Z80 DART (SIO), Z80 PIO, Z80 CTC, modem, RTC, and the keypad/display. It’s a cookie cutter Z80 SBC design, which makes development pretty easy. They are plentiful and cheap on the used market due to the lack of PCI security (tamper proofing, end to end encryption, etc).


I was give this by another fellow computer enthusiast and have been planning alternative uses for it since.


I/O is through the DIN-8 serial port, and there’s no local storage. I have to use a terminal program for loading the BASIC application on every power-up. I’m trying to come up with a low impact modification for this terminal for extra storage and banked RAM so that I can run CP/M.



PCB with Z80 and support chips.

Running Grant’s Searle Nascom Basic,

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