|Re: Need crash course in HP41 HP-IL stuff|
Message #6 Posted by Tony Duell on 9 Mar 2007, 5:35 a.m.,
in response to message #3 by Les Wright
This is very informative.
I think right now the most useful addition I can think of is the diskette drive. I do have a floppy drive on my PC and tons of 3.5" floppies that are easily formatted as single density.
Actually, it's double density. The 1.44M disks are 'high density'.
However, there are 2 problems with using 1.44M disks (PC 'HD' disks) in the 9114. The first is that the coercivity of the media is different. The 2 values are close, but not the same. This may not be reliable.
The second is that the 'HD detect hole' -- the extra hole that tells the PC that it's an HD disk -- lines up with the disk-inserted sensor in the 9114's drive and the latter will not recognise it has a disk inserted. A bit of tape over the hole will fix that.
But personally I'd look for some real DD disks.
Does the PC based software for reading these disks work in DOS box under Windows XP, or do I need a proper pre-Windows 95 DOS machine? Is the disk format out of the 9114 drive readable under DOS and Windows XP, or would my computer simply regard such 3.5" single density floppies as unformatted disks?
A PC will not recognise the disks. The low-level format is totally different (the HP disk is 77 cylinders, 2 heads, 16 sectors/track, 256 bytes/sector, the PC (720K) format is 80 cylinders, 2 heads, 9 sectors/track, 512 bytes/sector).
The member who has been writing to me about the CMT RAM box/RS232 interface mentioned both the Extended I/0 Module and the Extended IL modules, like they were different things, but I must admit I have never heard of the latter and can't find a manual for it on the DVD. Can someone enlighten me?
The Extended IL module (XIL) was a third-party ROM that allowed the HP41 to easilly use the entire capacity of the floppy disk, to print listings efficiently on an 80 column printer, and so on.
I don't use it. If I need a program listing on 'wide' paper, I transfer the HP41 program to the PC, and run it through a couple of programs there that firstly produce a listing and then reformat it as I want.
I do have a small size serial port on my computer so I expect that if I got any RS232 interface I would need a 25-to-9 pin adapter to connect. Is it any more complicated than that? I did get a USB-to-serial adapter cheap once to try to connect the 48G to USB, but it doesn't work. I do know that an expensive Dynex adapter works with the 48G cable and an old serial mouse, but I took it back after I put the cheap one on order. False economy! I guess I could splurge the 50 bucks again and get another if I ever replace the computer for one without a serial port.
The 82164 RS232 interface has a male DB25 plug on it. An internal jumper block lets you configure it either as DTE (terminal) or DCE (modem). You will therefore need the right adapters to link it to your PC DE9 connector
Personally I find the only sane way to use the 82164 is to leave that jumper block in the 'DTE' position and wire up the appropriate cables to get the signals where I want them for the other device. But then I think nothing about taking a soldering iron to a bit of hardware.
The reason it was more complicated for me is that I wanted to be able to transfer HP71 binary files. This meant I couldn't use XON/XOFF handshaking, I had to use hardware handshaking (some form of handshaking/flow control is essential or you will lose characters). And the 82164 uses the handshake lines in a somewhat odd way.
Also, let's say I just got the disk drive and couldn't find the Extended I/O Module. Would I be able to do basic read/write operations to the disk without it? Does that basic functionality exist in an IL with only the disk and the HP-IL module?
Yes. You can use the disk drive with the normal commands for the cassette drive (they're in the ROM in the 82160 HPIL module, you don't need any other modules), but you can only use the first 128K of each disk. That's actually quite a lot of storage for an HP41, so you may be satisfied with that.