Over at vogons, Dave Dunfield (https://dunfield.themindfactory.com/dnld.htm) has been working on updating his DDLINK package to be able to bootstrap file transfer between machines via COM, LPT or NIC. This is a small package much like LapLink and other tools of yesteryear. LapLink could famously be bootstrapped using a simple set of DOS commands.
However, Dave noted that FreeDOS's "copy /b COM1: DDBOOT.COM" strips various non-printable characters (https://www.vogons.org/viewtopic.php?p=1129367#p1129367), including EOF which should end the transfer. See other notes extracted from DDLINK.ZIP (https://dunfield.themindfactory.com/dnld/DDLINK.ZIP) below. Smells like a bug in FreeCOM's copy (https://github.com/FDOS/freecom/blob/master/cmd/copy.c). %<-----------------------------%<------------------- 3.4.1 FreeDos I have confirmed that this works well with several versions of MicroSoft MS-DOS, as well as IBM PC-DOS ... but it has more trouble with FreeDos! Both MS-DOS and PC-DOS provide an "almost binary" transfer when you perforn: COPY COMn: file In fact, the only character which can NOT be copied this way is 0x1A (EOF which stops the copy). To be able to copy on a bootloader, I only had to make sure it does not contain the byte value 0x1A. FreeDos however blocks more byte values. DDLINK 1.7+ bootloaders have been modified to contain NONE of the ones I've (so far) identified ... and it does work *sometimes* if done right after booting! I've not found /B to be reliable under FreeDos. If you have trouble using /B, please use the information below to try and determine which bytes are being blocked and contact me. These are the bytes I've observed that FreeDos blocks/corrupts: 00 NULL Often terminates strings 03 Control-C Console Interrupt 0A Line-feed ..probably related to 'newline' 0D Return ..difference between DOS & UNIX 11 XON resume output \ used in UNIX 13 XOFF suspent output / but not DOS 1A EOF Terminate file !There is no guarantee these won't change with new releases! These are the byte values DDLINK currently COPYs during bootstrap: 01 02 04-09 18 19 1C 26 31 34 36 38-3E 46 47 4A-4D 58 5F-61 64 68 6B 6F 72 73 75-7A 7E-83 85 88-8A 8C 8D 90 9B B0 B1 B3 B9 BB-BD C0 C1 C3 C7 CE D0 D2-D4 D6 DA-DC DF E0 E2 E3 F0 F1 F5 F6 F8-FF _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
