Accessing La Cueva BBS in Mexico in 1993
by Óscar Toledo G. Oct/05/2026
My predominant pc in 1993 was a Zilog Z280-based homebrew pc with 512 KB of RAM. It had a VGA card for show, a 3 1/2″ floppy disk drive, and connectors for serial ports, and printer port.
I acquired a discarded Hayes modem with the wonderful velocity of 2400 bauds. For some motive it did not had the highest of the case, it was a cumbersome black lengthy field. But it was simple to interface, and I used loads of time to write down a serial terminal program.
The Internet did not existed but, and the details about serial protocols and AT instructions got here from books, the identical because the ANSI escape sequences. The serial protocol was RS-232C, and comparatively simple, simply take a letter from the enter and show it on the display, take any letter from the keyboard and ship it again. I did not even fear about flow-control, as a result of the UART was set to 2400 bauds, the identical because the modem. Hardware flow-control utilizing RTS/CTS pins turned widespread when the 14400 bauds modem appeared, because the UART would should be set at 19200 bauds (sooner than the modem)
The AT instructions additionally had been comparatively easy. For instance, ATDT5551234 means to dial the quantity 5551234 utilizing tones. Although in Mexico in 1993 we nonetheless used ATDP5551234 to dial utilizing pulses.
The ANSI escape sequences are fashioned by the Esc character (0x1b) adopted by the opening sq. bracket [ some numbers, and a letter that signalled the command. For example, Esc [2J mean to erase the screen. Esc C moved the cursor to the right, and ESC[0;35m set a magenta color for the letters. I implemented all these escape sequences on my terminal program.
However (and luckily for this article), the book and the real usage differed slightly. So some BBS would look weird. To solve this, I implemented a capture buffer in my terminal program. The Z280 allows for MMU access to a 64K area, so I programmed it to save every received byte sequentially. When the display differed from what I expected, I would give a look to the escape sequences, and most of times found a small deviation that I could correct in my program.
Almost nothing was saved from that time, but for some reason in one of my modem sessions, I saved a whole 64K buffer of my activity calling La Cueva BBS. Just a file CUEVA.TXT I found on one of my old floppy disks, saved after February 11, 1993 (I know this because the BBS displayed the last logon time), and the session was from 9:30pm to 9:47pm, also reported by the BBS. You can see I downloaded a file, but the data for it wasn’t captured as only the displayed data was captured. You can even see trash when the phone line failed, and also that the data overrun the 64k buffer (you can notice La Cueva BBS replay starts with the log off message)
One thing that couldn’t be preserved was the keystroke timing, so the screens change very fast. But probably I took several seconds to read each screen.
There were also other BBS at the time like Catarsys. I think La Cueva BBS disappeared by 1994 or 1995, along all the remaining BBS. The sysop just put a temporary message, and soon the phone ceased to answer.
Header set Access-Control-Allow-Origin "https://nanochess.org" Header set Access-Control-Allow-Methods: "GET" Header set Access-Control-Allow-Headers "Content-Type, Authorization"
I’m glad I found this file, because watching it again brought memories, and surprisingly enough some of my friends didn’t had an idea this BBS existed. Enjoy it!
Update Oct/06/2026: I found a list of BBS phone numbers dated 1993. It was displayed as an alternate help page in my terminal program. I’ve redacted my passwords. Also I found another BBS capture, it is Nopal BBS; you can select the replayed one in the selection control just above the terminal screen.
BBS name Phone Bauds Hours User number
A-BBS 604-39-57 2400 18:00 -> 06:00
Amiga BBS 877-44-79 2400 21:00 -> 09:00
CatarSYS 282-06-82 14400 24 hrs. 355
Chip support 566-96-65 2400 21:00 -> 01:00
Computron BBS 519-71-63 2400 19:00 -> 09:00 145
Cosmic Odyssey 544-48-21 2400 22:00 -> 06:00
Inter-BBS 251-60-89 14400 22:00 -> 06:00
La Cueva de Atari 659-56-72 14400 24 hrs. 166
Macro BBS 539-61-05 2400 18:00 -> 23:00
Maldito BBS 552-04-02 2400 18:00 -> 06:00
Nopal BBS 689-32-58 14400 24 hrs.
Tierras extra§as 659-76-78 14400 24 hrs.
SIDCE BBS 250-06-40 14400 24 hrs.
SPIN 628-62-00 14400 24 hrs.
UIA BBS 570-79-37 2400 20:00 -> 08:00
USS Nova 577-55-44 2400 21:00 -> 09:00
VECTOR BBS 594-51-39 14400 19:00 -> 06:00
Related links
Last modified: Oct/05/2026
