Read IBM tapes on PDP-11/70 with Basic-Plus

Don’t know how far I’ll take this. It’s an interest today…maybe not tomorrow.

Since I made progress converting EBCDIC data…

“I found this which says simh can read the aws format. And since I already have some valid fake customer aws tape files from my Hercules work, it’s one less thing I have to do. However the tapedump program is giving me “error while loading shared libraries: cannot open shared object file: No such file or directory”. So for now I’m going to try and get my version of his Basic program working. But I need to download/install FreeBasic.

OK. installing/using FreeBasic worked!

So I have an AWS tape I created and this is what tapedump tells me about it…

bill@bill-MS-7B79:~/MyStuff/Computer_Simulator_Emulator/Emulators/Mainframe/Hercules/Tape/awsutilb-whb$ ./tapedump INPUT:
TAPEDUMP v1.0 (BASIC) copyright Jay Moseley, CCP 2000
Processing AWSTAPE file:
Serial Number from VOLume 1 label: VOL001
File MVT Dataset RECFM BLKSIZE LRECL BlocksExpected BlocksRead
0001 CUSTOMER.FILE B    16,400   164             10         10

I can tell by my filename that there are 1000 records. And if I append a D to the command I will get record detail, so I can tell where the fields begin.

One more thing. Although I successfully created the EBCDIC conversion data. In looking at Jay’s tapedump program. I see he has the more conventional way to build this data, with…DATA statements. Which is how I believe we did it…back in the day. However since I already had the data in Julia format, I just converted that to Basic-Plus. But I can borrow these DATA statements from his program…if I decide to be more conventional. And it is easier to understand. However he uses strings of Hex characters. I believe we just used base 10.