Bizarre 64
Encyclopedia
Bizarre 64 http://atchison.net/bizarre64bbs.htm
was a bulletin board system
written for the Commodore 64
by Bill Atchison circa 1985 in order to fill the need for a faster and more professional BBS system than was currently available at the time for the Commodore-64 computer system.
The problem faced with the Commodore-64 was that the disk drives were being run as serial devices transmitting data roughly at 1200 or 2400 bit/s which is about the same speed of the average modem at the time. Visitors to a typical Commodore-64 BBS would see the data stream visibly stagger and wait online for many seconds as the BBS switched from modem output to disk access for more data. Therefore, the challenge of the Bizarre-64 BBS was to eliminate all of the waiting and make the data transfer appear transparent to the visitor and look as smooth and fast as competitive products running on more expensive hardware.
How Bizarre-64 resolved this problem is that the disk drives and modem
could actually transmit data simultaneously so by caching a partial index of the BBS in memory certain information could be flushed to the modem output buffer immediately while the computer was waiting on the disk to transfer the data. Since the disk drives had their own on-board computers commands could be sent to locate and transfer records asynchronously without the program needing to wait for events from the disk to complete. Bizarre-64 leveraged this capability by always sending requests in advance to the disk drive and then would output a stream of data to the modem while waiting on the next record from the disk drive. This technique made Bizarre-64 very responsive to the visitor so that actions such as NEXT or PREVIOUS message seemed to happen instantly upon pushing the letter.
Additionally, Bizarre-64 could support rapid login and membership search for up to 4,000 members via a hash index table stored in ghost RAM
hidden behind an 8K ROM
. This allowed logins and user name searches to be extremely fast in 1-2 seconds as using the hash table
located the member name with a mathematical formula thus requiring only a couple of disk accesses to identify the exact member record. This was a massive improvement over other systems that searched linearly through a member database that could take almost a minute or more to locate a record.
was a bulletin board system
Bulletin board system
A Bulletin Board System, or BBS, is a computer system running software that allows users to connect and log in to the system using a terminal program. Once logged in, a user can perform functions such as uploading and downloading software and data, reading news and bulletins, and exchanging...
written for the Commodore 64
Commodore 64
The Commodore 64 is an 8-bit home computer introduced by Commodore International in January 1982.Volume production started in the spring of 1982, with machines being released on to the market in August at a price of US$595...
by Bill Atchison circa 1985 in order to fill the need for a faster and more professional BBS system than was currently available at the time for the Commodore-64 computer system.
The problem faced with the Commodore-64 was that the disk drives were being run as serial devices transmitting data roughly at 1200 or 2400 bit/s which is about the same speed of the average modem at the time. Visitors to a typical Commodore-64 BBS would see the data stream visibly stagger and wait online for many seconds as the BBS switched from modem output to disk access for more data. Therefore, the challenge of the Bizarre-64 BBS was to eliminate all of the waiting and make the data transfer appear transparent to the visitor and look as smooth and fast as competitive products running on more expensive hardware.
How Bizarre-64 resolved this problem is that the disk drives and modem
Modem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
could actually transmit data simultaneously so by caching a partial index of the BBS in memory certain information could be flushed to the modem output buffer immediately while the computer was waiting on the disk to transfer the data. Since the disk drives had their own on-board computers commands could be sent to locate and transfer records asynchronously without the program needing to wait for events from the disk to complete. Bizarre-64 leveraged this capability by always sending requests in advance to the disk drive and then would output a stream of data to the modem while waiting on the next record from the disk drive. This technique made Bizarre-64 very responsive to the visitor so that actions such as NEXT or PREVIOUS message seemed to happen instantly upon pushing the letter.
Additionally, Bizarre-64 could support rapid login and membership search for up to 4,000 members via a hash index table stored in ghost RAM
Ram
-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
hidden behind an 8K ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
. This allowed logins and user name searches to be extremely fast in 1-2 seconds as using the hash table
Hash table
In computer science, a hash table or hash map is a data structure that uses a hash function to map identifying values, known as keys , to their associated values . Thus, a hash table implements an associative array...
located the member name with a mathematical formula thus requiring only a couple of disk accesses to identify the exact member record. This was a massive improvement over other systems that searched linearly through a member database that could take almost a minute or more to locate a record.