website/content/museum/ice-felix-hc-91.md

title, categories, types, origins, years, cpus, params

title	categories	types	origins	years	cpus	params
Ice-Felix HC-91	Computers	Home Computer	Romania	1991	Z80-A	name image company company_name specs tabs forum_thread photos hardware links docs related oc_id source HC-91 /media/museum/photos/icefelix_hc91b_system_2.jpg /companies/ice-felix Ice-Felix label value NAME HC-91 label value MANUFACTURER Ice-Felix label value TYPE Home Computer label value ORIGIN Romania label value YEAR 1991 label value END OF PRODUCTION 1992 label value BUILT IN LANGUAGE Spectrum Basic interpreter label value KEYBOARD Mechanical 40 or 50 keys (EDIT, TAB, CAPS LOCK, CAPS SHIFT, EXT MODE, DELETE, RETURN, GRAPH, SYMBOL SHIFT, arrow keys) label value CPU Z80-A label value SPEED 3.5 Mhz. label value RAM 64 KB label value ROM 16 KB (Spectrum O.S. and BASIC) label value TEXT MODES 32 columns x 24 lines label value GRAPHIC MODES 256 x 192 pixels label value COLORS 16 (8 colours in normal or bright modes) label value SOUND Beeper (10 octaves) label value SIZE / WEIGHT 34 (W) x 25 (D) x 4 (H) cm. label value I/O PORTS Tape recorder (DIN5), expansion bus, joystick (DB9), power in, RGB (DB9), TV aerial video output (cinch) label value POWER SUPPLY External AC adaptor. Built-in power regulation label value PRICE 7000 lei (Romanian money) - About $233 photos hardware links docs 618 title subtitle text image 40-KEY VERSION The HC-91 40 (colored) keys version. HC-91 uses 40 mechanical keys. That is the main weakness of the microcomputer (after long periods of inactivity, keys need to be "formed" because of oxidation). /media/museum/photos/icc_hc91a_system_1.jpg title subtitle text image 40-KEY CLOSE-UP /media/museum/photos/icc_hc91a_keybclose_1.jpg title subtitle text image 50-KEY CLOSE-UP /media/museum/photos/icefelix_hc91b_keybclose_1.jpg title subtitle text image HC-91 LOGO /media/museum/photos/icc_hc91_logo_1.jpg title subtitle text image THE MOTHERBOARD The system needs 46 chips instead of 80 in the HC-85 version. The HC-91 computer have 2 X 4464 DRAMS (64K X 4 bit each), and a strange video sequencer with discrete IC's. This sequencer runs synchronous with the CPU clock, at the exact time when CPU don't access the "video" area. There was no special video RAM IC's, and no wait states or CPU clock blocking. The main board have all hardware support for CP/M, including a system BIOS, with the exception of the disk controller. The CP/M use 56 KB of RAM plus 8 KB video logic bank Mainboard provides 64 holes **(6)** for specific EXTENSION BOARD, wich can be mounted at bottom. A 64 or 96 female connector can be used on the computer, the extension has the male connector.\ Some variants have been produced with extension incorporated. In this variants, the bottom connector was doubled, in the middle (mainboard-extension, with rectangular hole for 64-pin connector). In this way, standard HC-EXTENSION's could be home-mounted by hobbysts **(1)** TV Aerial UHF modulator\ **(2)** Video RGB out DB9 plug\ **(3)** Power plug. An external AC adaptor supply the power\ **(4)** Joystick DB9 connector\ **(5)** Microprocessor Z80-A East-European version\ **(6)** Extension board holes\ **(7)** 16 KB ROM chip holding the Spectrum BASIC interpreter\ **(8)** Two 4464 chips (64K x 4 bits) holding 64 KB of RAM\ **(9)** Tape recorder DIN plug /media/museum/photos/icc_hc91_motherboard.jpg title subtitle text image CHIPS CLOSE-UP Note the East-European Z80 microprocessor beside a Japanese 16 BK Eprom. /media/museum/photos/icc_hc91_proccloseup.jpg title subtitle text image CHIPS CLOSE-UP #2 Many east-European chips (Kxx series) in this board area /media/museum/photos/icc_hc91a_boardclose_1.jpg title subtitle text image INSIDE THE CASE COVER Keyboard back side\ Voltage regulator and its cooler\ Loudspeaker. /media/museum/photos/icc_hc91_insidekeyb_1.jpg title subtitle text image REAR CONNECTORS **(1)** Tape recorder DIN plug. Input from TAPE has an AO amplifier without negative reaction for TTL signal formatting. Output has only a resistive divider from output port pin.\ **(2)** 54-pin connector for external extension. The pinouts are Spectrum compatible at CPU lines, but there are significant differences for other lines\ **(3)** DB9-Male, input from joystick, mapped directly to the numerical keys\ **(4)** Power plug. An external AC adaptor supplies the powerpower supply. HC has an internal power regulator LM 323 (5V/3A)wich produces 5VCC. Boards with ALS needs aprox 0.7 Amps at 5V, without extension.\ **(5)** DB9-Female, output for RGB monitors with intensification, TTL compatible\ **(6)** Output from TV modulator, PAL encoded using an PROM and SCLK:4 (system clock divided by 4)\ **(7)** Reset switch (beside the keyboard on the 40-key version) /media/museum/photos/felix_hc91_back_1.jpg title subtitle text image HC-91+ See information about the HC-91+ in the "More information" section. Thanks to **Grecu Cristi** /media/museum/photos/icefelix_hc91plus_system_s2.jpg title subtitle text image HC-91+ EXPANSION CARD IF-1 expansion card connectors, from left to right: • Two jacks for local network.\ • DB9 serial RS232C connector\ • FDD connector\ • Expansion bus connector\ • Power supply connector. If the card is not powered or connected, the computer still works like an ordinary HC-91. Thanks to Grecu Cristi /media/museum/photos/icefelix_hc91plus_expboard_s1.jpg title subtitle text image COMPLETE SYSTEM HC-91 with extension board and additional case. This special system was 'home made' by Daniel Ioan from various parts available at ICE factory. **(1)** Handmade NMI button (No Maskable Interrupt)\ **(2)** Tape recorder DIN plug\ **(3)** Extension connector 2 from extension board\ **(4)** Extension connector 1 from computer board\ **(5)** Handmade Parallel port, not Centronics compatible\ **(6)** Joystick connector\ **(7)** Floppy disc connector (extension board)\ **(8)** Power supply connector\ **(9)** Serial interface\ **(10)** RGB TTL video output\ **(11)** Network jacks\ **(12)** TV/RF modulator Thanks to Daniel IOAN for picture and explanations /media/museum/photos/icc_hc91_extendedsys.jpg title subtitle text image ICE JOYSTICK INTERFACE ICE Felix made several peripherals for its HC series, among them:\ • this joystick interface,\ • A Sinclair comptatible joystick,\ • A tape recorder\ • And even an optical pen. The joystick interface is Sinclair Kempston compatible; it uses port 1 of the computer. The jack is used to plug in an optical pen. Thanks to **Grecu Cristi** /media/museum/hardware/felix_hc85_joyinterf_s1.jpg title subtitle text image ICE SINCLAIR COMPATIBLE JOYSTICK Thanks to **Grecu Cristi** /media/museum/hardware/felix_hc85_joystick_s1.jpg title subtitle text image ICE TAPE RECORDER The mecanical part of this tape recorder looks strongly "inspired" with the one from Spectrum +2. Thanks to **Grecu Cristi** /media/museum/hardware/felix_hc85_cassetterec_s1.jpg title subtitle text image ICE LIGHT PEN The light pen is a very simple device, containing a photodiode. It is connected to the jack of the joystick interface. When the electron beam is crossing the area of the screen where the light pen is positionend, it sends a signal to the interface, that resets bit 1 of port 191 of the HC. Thanks to **Grecu Cristi** /media/museum/hardware/icc_hc91_lightpen_s1.jpg title url text Romanian users group http://groups.yahoo.com/group/RomanianHomeComputer/ They have rare documentations, programs and useful PC utilities for Romanian computers title url cover text HC91 - USER'S MANUAL http://george.chirtoaca.googlepages.com/ /media/museum/docs/couvs/ice-felix_hc91_manual.jpg [**HC91 - USER'S MANUAL**](http://george.chirtoaca.googlepages.com/)written by Ice-Felix  compiled/archived by George Chirtoaca\  type of document : PDF\  size : 3 MB\  source : [george.chirtoaca.googlepages.com](http://george.chirtoaca.googlepages.com/) title url cover text INTERFATA 1 HC - USER'S MANUAL http://george.chirtoaca.googlepages.com/ /media/museum/docs/couvs/ice-felix_hc91_if1_manual.jpg [**INTERFATA 1 HC - USER'S MANUAL**](http://george.chirtoaca.googlepages.com/)written by Ice-Felix  compiled/archived by George Chirtoaca\  type of document : PDF\  size : 3 MB\  source : [george.chirtoaca.googlepages.com](http://george.chirtoaca.googlepages.com/) /museum/ice-felix-hc-2000 /museum/ice-felix-hc-85 632 url date https://web.archive.org/web/20230329012302/http://www.old-computers.com/museum/computer.asp?c=632 2023-03-29

The HC-91 is a Romanian ZX-Spectrum clone. Two versions of the HC-91 computer were manufactured by Ice-Felix.

The first one used the same case and the same keyboard as the HC-85 with coloured keys for only external difference. This version was also sold with the HC-90 name.
The second one featured a new 50 keys keyboard design (picture). Thanks to two small rectractable feet, the keyboard can be tilted.

Also, the motherboard was completely redrawn to take account of the new memory chips (only two 4464 memory chips was needed instead of 24 chips in the HC-85 version). No additional feature was added and the systems were always pure Sinclair Spectrum clones, but also CP/M compatible machines if a disk extension was used.

Despite the use of many components from Eastern Europe, one finds however several Japanese, American and even Brasilian chips.

An HC-91+ was also produced, it featured a daughter board with three interfaces: 5,25" floppy disk drives, serial RS232 and local network. (See the Read More section for more details)

production of HC-91 was stoped in 1992, when Ice-Felix lunched the HC-2000, which had same basic features as the hc-91 plus built-in floppy disc drive, and hardware upgrades.

The last HC model was a 386SX PC compatible with 1 MB ram, vga, buit-in 3.5 floppy, apox. same case as HC2000 and TV and monitor conectors. An optional 40-100 MB hard disk could be added. The computer was available a year or two and it didn't sold very well.