Code Master CWR-610E

R100 from the CTARC including a monitor. The CWR-610E decodes CW and RTTY and displays the text on a CRT. As I said before, these days we do this and more with a PIC. But... R100.

The Code Master CWR-610E is a CW and RTTY reader that displays the received text on a CRT monitor or TV set. It also has a random CW generator for morse code practice.

The DPO fitted a frontpanel jack with a little piezo speaker in parallel with it. Putting a plug in the socket silences the speaker of course.

I wonder who PACO was (see logo next to the external speaker jack).

The CWR-610E is based on a Motorola 6802 microprocessor, with a 6821 PIA and a 6845 CRTG. There's 1 kilobyte (2 x 2114) of static RAM for the video memory, but no other RAM devices -- the 6802 has 128 bytes on-board however.

The code is in a 4 kilobyte 2732 EPROM. I've disassembled some of it and... it's interesting. But I suppose if it works it works. An example:

; Fill $2000 to $27FF with $8A
78E9                 ldx     #$2000
78EC                 bra     loc_78F1
78EE                 ldx     #$2000          ; Some redundancy here
78F1 loc_78F1:       ldaa    #$8A
78F3 loc_78F3:       staa    0,x
78F5                 inx
78F6                 cpx     #$2800
78F9                 bne     loc_78F3
78FB                 rts

This clears the screen, I would think ($800 is two kilobytes, and the video RAM is only one kilobyte, but there's no other RAM on the board, so who knows). In any case, the first two lines serve no purpose, entry could be via $78EE rather than $78E9. There's a lot of this kind of strangeness in the code. This points to hand assembly and patching I would think.

You can download the manual from DC7XJ's page. The very first issue of Ham Radio Today has a review of the CWR-600. Conclusion: not very good.